No need to be afraid of this document. If it existed, Matthew and Luke used it. If they weren’t afraid, why should you be?
In this article (Part Seven) and the previous two (Part 5 and Part 6), we explore what was happening between Jesus’ ministry and the written Gospels. Here we turn our attention mainly toward so-called Q.
Once again, this article deals with this gap:
Jesus’ ministry | | Written Synoptic Gospels
The disciples were learning and observing important aspects of Jesus’ ministry while it was fully active. The disciples transmitted their observations and lessons to the earliest churches after his ministry. So the little vertical bars are not intended to be firm.
Concerning that gap, though, we can still ask these questions: Do sources, such as so-called Q, feed into the Gospels? Did these sources exist at all, or are they hypothetical? If they existed or still exist in some way, where do scholars find them? Do the sources secure the Gospels’ historical reliability? After all, don’t other Greco-Roman authors use sources?
We focus mainly on Matthew and Luke, from which scholars extract Q.
This article may be unsettling for some readers. Maybe by now they have clicked out of it. “Not for me!” However, skeptical scholars seem to ache to bring up these issues on television and radio and in popular print.
So the Church of all denominations should not avoid these questions and challenges. We should be confident about Scripture, for solid reasons, not blind faith. I learned a lot while writing this article. My faith has been built up. Education really is the best antidote to popular confusion and challenges.
As usual, here are my reminders: Matthew, Mark, and Luke have a lot of passages in common, so they are called the synoptic Gospels (synoptic means viewed together). The authors are sometimes called synoptists. Slashes // mean parallel passages among them. The writers of the four Gospels are also called evangelists.
This article (Part Seven) in a long series is on the historical reliability of the Gospels. The series has nothing to do with their inerrancy or inspiration, though nothing in this article contradicts those doctrines.
Hovering over the references below will bring up the NET Bible version on each of these.
1. What does “Q” mean?
It certainly has nothing to do with a character in a James Bond movie or a saint, as in “the Gospel According to Saint Q.” Rather, it comes from the German word Quelle, which means “source.” It was abbreviated to Q, which was widely accepted as the designation of special material.
2. What special material?
When you read the synoptic Gospels, you see many similarities. And on a more careful reading, you can also observe verses that Matthew and Luke seem to share, but Mark does not. The common material only in Matthew and Luke is called Q. It’s that simple, for our purposes. To go beyond this point leads us into complications.
3. Is Q a Gospel?
That depends on whether we are talking about genre (kind of writing) or definitions. In Greek, euangelion means “good news.” So according to that definition, Q may be considered a gospel, for as we shall see in Q & A Ten, below, it teaches good news like the anointing of Jesus at his baptism, his power over Satan, and Spirit baptism.
However, if we are talking about genre, then the four Biblical Gospels are narratives or stories, and stories, incidentally, do not have to be fictional, but they can be true. As a whole, Q is not a flowing narrative (see Q & A Seventeen, below, for the implications of this). In that sense, Q is not a Gospel, because it is made up of sayings with one or two short narratives. However, at least one scholar sees a narrative framework for Q (Stephen Hultgren), but the framework is nevertheless harder to detect than that in Matthew and Luke.
4. Did Q even exist?
Some scholars doubt that it ever existed, but many conclude that it did. Extracting verses out of Matthew and Luke, John Kloppenborg put together the standard (simplified) reference on the Q sayings (see References and Further Reading section, below). Only in that derivative, extracted sense does Q exist today.
This apologetics website provides some examples of parallel passages in a very short article. The writer also answers whether Q takes away from the inspiration of Scripture. Q does not. But since my article is not about inspiration, let’s move on.
We shall see in Q & A Nine that Q, if it existed, may have also been transmitted orally, or it may have been transmitted both in oral and written forms, at different stages or at the same time. The history of a hypothetical document can get complicated!
5. Are the parallel passages exact?
In Kloppenborg’s compilation, he underlines the exact wording between specific parallel passages in Matthew and Luke (see the link in the previous question for examples). However, more often than not, the wording is not exact. In fact, one of the extraordinary features of the Q passages is how infrequently the parallel verses are identical.
In “The Lost Gospel of Q: Fact or Fantasy?” Eta Linnemann tabulates the percentages of the exact parallels in Q’s wording. The results are not high. For that and other reasons she concludes that Q is a fantasy. The article is written in English.
6. How many passages are extracted from Luke and Matthew?
Matthew and Luke have around 230 verses in common, but the number can vary (scholars do not agree on the details). Scholars have arranged the verses in topics. One list of topics adds up to forty-nine, with several verses under any one topic (Chilton and Craig, pp. 11-12). Kloppenborg’s reference work comes up with sixty-eight sections or pericopae (plural of pericope or unit or marked-off passage). Several or many verses fit under each section. Only a few of these topics cluster together thematically. So much of Q appears disjointed.
7. What is the case for Q?
Three reasons, among others not dealt with here, point toward the existence of Q.
The verbal agreements between parallel passages in Matthew and Luke are close, at times identical (see Q & A Four and the link there). Many scholars say that the similarities cannot be coincidental. They certainly do not believe that it comes from divine inspiration. (Even basic Christian doctrine says that the authors’ minds were intact while the authors wrote; inspiration is not mechanical). Plus, there are too many other factors at work, such as the differences in the details.
The second is the order that Matthew and Luke share in their use of Q. “In at least 85 percent of the Q traditions it is possible to ascertain the common order or to determine which Evangelist disturbed the common order” (Stanton, p. 645).
Another document, which supports the existence of Q by analogy, of sorts, is the so-called Gospel of Thomas, not actually written by the Apostle Thomas, so it is pseudonymous. It is a collection of sayings, not a flowing story as the four Gospels are. The Thomas collection of sayings looks somewhat like Q. However, Thomas comes much later than Q and is derivative from the Biblical Gospels. So this parallel support is tenuous.
8. What is the case against Q?
Two major factors work against Q’s existence or at least its existence as a written document.
One is the two-Gospel hypothesis, to be distinguished from the two-document hypothesis (see Q & A Sixteen). This two-Gospel hypothesis says that Matthew was written first, and Luke used Matthew, and Mark was dependent on both, though our focus is on Luke’s use of Matthew. Thus, the need for Q evaporates. However, the two-Gospel hypothesis is not as simple a solution as one might expect.
To cite only two examples challenging the claim that Luke used Matthew, Matthew has the long Sermon on the Mount (chapters 5-7), whereas Luke has the shorter Sermon on the Plain (6:17-49). Other passages in Matthew’s sermon are scattered throughout Luke. If Luke used Matthew, it is difficult to explain why he would omit so much of the sermon and place other verses from it elsewhere. As to the second example, in Matt. 10, Jesus sends out the Twelve on their first commission to preach. But those verses are scattered in seven different chapters in Luke. Many other examples could be offered, and so could the replies to the objections, but all of this shows that the two-Gospel solution may not be the best one; it certainly is not simple (see Carson and Moo, Guthrie, and Stanton, for more discussion).
A second objection to Q challenges whether it originated and remained in a written form. The objection compares the Gospel material itself. In Jesus Remembered, New Testament scholar James D. G. Dunn places parallel passages side by side for many pages (pp. 210-54). The differences – not the similarities – between the pericopae can best be explained by the oral process of passing on traditions, so he says. If Matthew or Luke had a written source in front of him, the differences would not be as frequent and pronounced as Dunn indicates, even after we factor in the Synoptists’ theological purposes that lead to variations.
Dunn does not deny the existence of a written Q or perhaps other written documents in the earliest Christian communities (p. 237), but such sources are not the whole picture. Nonetheless, an oral tradition process diminishes the existence of a self-contained written source, unless scholars assume that Q also originated and remained in oral form, in addition to its written form, until Matthew and Luke incorporated it. This is indeed what some scholars assume (see Q & A Nine, next).
For more objections, see the link in Q & A Five, above.
9. So was Q passed on in oral and written forms?
Very probably, if it existed, as such. Some scholars conclude that Q was intended to be delivered in oral performance (see Horsley, below). Some scholars assume that pericopae of Q may have been handed down orally, but other passages were written down early. One scholar applies chronology to the problem: “Without disputing Q’s existence in a fixed written form, we must allow some influence of the oral tradition between the time of its crystallization and its use by the two Synoptists” (Vassilides, p. 143). He also concludes that by the time Matthew and Luke used Q, it existed “in a fixed written form” (p. 160, emphasis original).
James M. Robinson is one of the foremost scholars on Q (see References and Further Reading section, below). For him, it is not a question that Q existed in written form. “The history of the synoptic tradition is no longer dependent only on the forms of oral transmission, but now has a series of written texts bridging much of the gulf back from the canonical gospels to Jesus” (“A Written,” p. 61)
10. What does Q teach?
The Q material supports many aspects of the gospel, but it is impossible to reduce Q to only a few themes or purposes because the content of Q is so diverse. Here is a representative, partial list. Scholars follow Luke’s order ahead of Matthew, so the first set of references comes from Luke, the second set from Matthew.
- Empowerment for ministry: The Holy Spirit anoints Jesus at his baptism ( 3:21-22 // 3:16-17)
- Divine relationship: Father’s proclamation of the Sonship of Jesus at his baptism ( 3:22 // 3:17); unique intimacy between the Father and the Son ( 10:21-22 // 11:25-27)
- Spirit baptism: Jesus will baptize with the Holy Spirit (3:15, 16-17 // 3:11-12)
- Title: The Son of Man (several passages; for example, see the last item, below)
- Jesus’ power over Satan: Jesus’ victory during temptation (4:1-13 // 4:1-11); power to cast out demons ( 11:14 // 12:22)
- Beatitudes (6:2-26 // 5:1-12)
- Discipleship: love of enemies (6:27-36 // 5:39-42, 44-48; 7:12); hearing and doing the words of Jesus (6:47-49 // 7:24-27); no anxiety (12:22-32 // 6:25-34); losing our life, picking up our cross, and following him (14:27; 17:33 // 10:38-39)
- Healing: the centurion’s servant (7:1-10 // 7:28a: 8:5-10, 13)
- Summary of Jesus’ miracle ministry: the blind see, lepers are cleansed, deaf hear, dead are raised, poor are given good news ( 7:22 // 11:4-5)
- Prayer: asking, seeking, knocking, and getting good answers (11:9-13 // 7:7-11)
- Public confession of a disciple: Jesus acknowledges before the Father those who acknowledge him before humans (12:8-9 // 10:32-33)
- Eschatology: Coming of the Son of Man ( 12:39-40 // 24:43-44; see also 17:23-24, 26-30, 33-35, 37 // 24:26-28, 37-41; 10:39)
This selective list supports the miracles and divinity of Christ and key teachings in the Gospels. What is most interesting is an early expression of Trinitarianism, though the Q passages do not detail the doctrine (see the first two items). The passages, as written, certainly do not deny the Trinity, but show the Father and the Holy Spirit blessing the Son at his baptism. Also, Q says that Jesus will baptize his followers with the Holy Spirit – Spirit baptism, perhaps shockwaves of Pentecost. Finally, the Son of Man “in his day will be like the lightning, which flashes and lights up the sky from one end to the other” (17:24 // 24:27). This saying reveals a divine figure coming back from heaven.
So why wouldn’t these items cohere with other Biblical teachings, especially in the Gospels? Didn’t Luke and Matthew (allegedly) incorporate Q, thereby approving and endorsing it? Didn’t Luke say in his preface that he researched other accounts? Granted, Q as such is not an “account,” but Luke’s preface shows that other information was circulating about Jesus.
11. What’s missing from Q?
The most conspicuous absence is the passion and resurrection narrative (but see Q-&-A’s Twelve and Thirteen, below). “Passion” in this context means “suffering.” “Narrative” means “story,” and a story does not have to be fictional. It can be true. (In this and the next two Q-&-A’s, I do not distinguish between narrative and kerygma or preaching for my purposes here.)
Anyway, in the synoptic Gospels, the passion narrative begins with the plot to arrest and kill Jesus; it reaches a high point in his crucifixion; and it ends with his burial (Matt. 26-27; Mark 14-15; Luke 22-23). The post-Easter narratives, of course, end the Gospels. We can see them as one narrative, for our brief purpose here.
Although assuming a community or communities stood behind Q is tenuous, these questions have been asked: Does the silence on the crucifixion and resurrection in Q reflect the views of certain earliest communities? Did they not believe that Jesus was crucified? Did they not believe that he was resurrected?
Some scholars say yes. But that’s a classic argument from silence. Also, even New Testament scholars like Rudolf Bultmann (1884-1976), who was more radical than most, disagree. The proclamation of the cross and the post-Easter story was much too widespread for communities neither to believe in the crucifixion (and resurrection) nor know about them. This is one reason that the four Gospels end in Jerusalem, at the foot of the cross and at the empty tomb, proclaiming Jesus’ resurrection. The cross and resurrection were also proclaimed, for example, in Corinth (1 Corinthians 15:1-8); Galatia (Galatians 1:1, 4:4-6); Jerusalem right after Pentecost (Acts 2:22-24); Thessalonica (1 Thessalonians 1:10); Rome (1 Peter 1:19-21). Paul and Barnabas taught in Antioch (Acts 11:19-30). Athens heard about the resurrection from Paul (Acts 17:16-34). Peter traveled throughout the country of Judea, Samaria, and Galilee, and his message included the crucifixion and resurrection (Acts 9:31-35; 10:34-43).
By analogy, in the Easter narrative, Luke’s mentions the ascension (24:50-53), whereas Matthew and John do not in their Easter narratives. The later ending in Mark does (16:19). All four Gospels mention the resurrection. Does this variation mean that these different “communities” (except the Lukan “community” and later-ending-Markan “community”) did not believe in the ascension, but only in the resurrection? Of course not. The Gospels that do not explicitly mention the ascension merely focus on other things. In a Christian context about the resurrection, the ascension is assumed, unless it can be shown, historically, that early Christian communities believed that the resurrected Jesus was still down here on earth somewhere, up to the time that these communities existed. This cannot be shown. It is very tricky indeed to draw conclusions from silence.
So it is highly unlikely that any early Q communities, if Q existed and if they existed around it, did not believe or did not know that the crucifixion (or resurrection) happened; the communities may have simply assumed them. After all, Q says that the Son of Man will returnextra-dramatically, like flashes of lightning, visible for all. So this implies that he was raised up to heaven. His being raised up implies his prior suffering or at least his death. Q, if it existed, simply focuses on other matters, such as Spirit baptism (echoes of Pentecost) and discipleship. Apparently, they were interested in the teachings of Jesus before the Passion actually took place. Christian communities are allowed to do this, without our drawing conclusions from their silence about other issues and beliefs.
12. Does Q embody pure and original Christianity?
This question seems innocent enough, but it implies more than Q can bear. On a more dubious perhaps sinister note from some scholars today, the question assumes that Q communities did not believe in or were unconcerned about the death (and resurrection) of Jesus, as we just discussed in the previous Q & A. Perhaps the communities did not even know about them. Some scholars assume that certain early Christians were “myth-makers,” and Q confirms this by not building up “myths” — never mind that Q teaches that Jesus shall return in flashes of lightning from the sky for all to see.
Since this skepticism circulates widely on the web, let’s deal with it here and in the next Q & A. Let’s allow a very prominent scholar to tackle the question. James D. G. Dunn points out three flaws.
First, some scholars assert that the Q document assumes that only one community had it. In reply, however, Dunn says that it is a fallacy to believe in one document per community. “It simply will not do to identify the character of a community with the character of a document associated with it.” And “the Dead Sea Scrolls should surely have banished forever the idea that communities possessed and treasured only one document or only one genre [kind] of tradition” (p. 150). Finally, “the absence of various themes from Q (e.g. purity issues and Torah) should not be taken necessarily as evidence of the Q community’s limited concerns, but may rather indicate that Q does not represent the whole concerns of the Q people” (p. 151)
Second, Dunn mentions the argument from silence, as we noted in the previous Q & A. “Of course it is incredible [not believable] that there were groups in Galilee who cherished the memory of Jesus’ teaching but who either did not know or were unconcerned that Jesus had been executed. In fact, Q does show awareness of Jesus’ death” (p. 151). Then Dunn references 6:22-23 // 5:11-12; 13:34-35 // 13:37-39; 11:49-51 // 11:34-36; 14:27 // 10:38.
Third, it is a fallacy to assume that “communities of disciples were isolated from one another and that documents were written only for the use of the scribe’s own community . . . But the evidence of our earliest sources is that communities maintained communication with one another; and it is more probable that tradition was written down in order to facilitate communication at a distance” (p. 152). Thus, Matthew and Luke had access to Q, and these Gospels were written at different times and places.
For me, what Dunn says here makes sense. In the next Q & A, let’s work out his points in a little different direction.
13. Do the Passion (Jesus’s sufferings) narratives throw any light on Q?
Indeed the narratives do. Many scholars believe that the Passion narratives existed in their own right and were used as sources earlier than AD 40; they were possibly written in some form, quite early. Eventually, they were assimilated into the Gospels. In a careful study of the four Gospels, Etienne Trocmé says that the Passion narratives originated in Jerusalem (pp. 83-89). He also concludes that they were used liturgically during the Passover pilgrimages of earliest Jewish-Christians.
Now let’s put some facts together.
- It is speculated that Q communities were based in first-century Galilee.
- Jewish-Christian pilgrims traveled up to Jerusalem during Passover and heard the Passion story from the church in the Holy City, says Trocmé (pp. 83-89).
- For example, Paul visited with Peter in Jerusalem (Galatians 1:18-19).
- Paul says that he received and handed on the tradition that Christ died for our sins, was buried, and was raised from the dead on the third day (1 Corinthians 15:3-4). Clearly, Paul’s receiving of this tradition occurred in Jerusalem (see Part Six and Q & A Three in that link). This confirms that the Passion traditions were early and essential and originated in Jerusalem.
So what do these facts mean? The Passion traditions are every bit as ancient as hypothetical Q is, even more ancient. I see the message of the suffering, death, and burial (and resurrection) of Jesus as shockwaves radiating out of Jerusalem, being part and parcel of the earliest traditions. The Q communities, if they existed, heard about the suffering, death, and burial (and victory) of Jesus during their pilgrimages and very likely took this message back to their communities. (The repetition of the message by ordinary pilgrims does not take away from official teachers’ role of preserving the traditions. The shock waves from Jerusalem influenced the entire early church — even outside Jerusalem, Judea, Samaria, and Galilee.
So, as Dunn noted in the previous Q & A, we should not draw questionable conclusions from the silence of hypothetical Q on the Passion traditions. Again, communities, if they existed around Q, are certainly allowed to focus on other doctrines for their own purposes. And Q surely does not represent the Q people’s entire concerns. Apparently, Q shows that they were interested in the teachings of Jesus before his passion actually took place. Indeed, we may draw the conclusion that the earliest communities in and around Israel heard and handed on and lived by the Passion story, whether they were connected to Q in some way or not. We should not believe the one document per community fallacy.
14. What’s the bottom line to the three previous Q-&-A’s?
We took some time with the issue of Q’s teachings and absent teachings because serious challenges to the Gospels’ integrity and to essential events in Jesus’ life have been launched in books and on the web. Here are the bottom line points:
- Let’s not forget that Q is a hypothetical document.
- Arguments from silence are too risky on which to build far-reaching conclusions.
- Assuming Q existed, we should not fall prey to the one document per community fallacy.
- The Passion traditions were deeply ingrained in the earliest Christian communities in and around Israel and beyond.
- Q alludes to Jesus’ death and says he will return with flashes of lightning. Death and return imply resurrection in an early Christian context.
- Therefore, the communities of hypothetical Q assumed the crucifixion and resurrection and merely focused on aspects of Jesus’ teachings that were delivered before his passion actually took place.
So I see no reason that critics can rightly use Q as a weapon against traditional Christianity.
15. Is Q the only source that feeds into Matthew and Luke?
In addition to hypothetical Q and the Passion narratives, some scholars postulate the existence of “M” or material unique to Matthew (hence the abbreviation “M”). An example is the Infancy narrative (1:18-2:23). They also speculate that material unique to Luke may have existed in its own right, which they label “L” for Luke. The Infancy narrative about John the Baptist and Jesus is an example (Luke 1:5-2:40). The future article on Matthew will hold out the possibility that Joseph himself may have originated parts of the Infancy narrative. And the future article on Luke will assert that Mary may have originated parts of the Infancy narrative.
See the link to Roberts’ blog, below, for a short summary and flow chart of sources.
16. What’s the bottom line for the historical reliability of Matthew and Luke?
We are examining the Gospels in their historical context, according to the standards of their own times.
It does not matter so much that hypothetical Q traveled down through earliest church history orally and then ended up written, or that it was oral and written at the same time. If it existed as such and if Matthew and Luke used it, then they approved and endorsed it, incorporating it into their Gospels or stories about Jesus. Q’s teachings cohere with the Gospels (see Q & A Ten). If Matthew and Luke used it, are we wiser than they? Under these conditions, if Q is not hypothetical, it can strengthen the reliability of Matthew and Luke.
Greco-Roman authors used sources, so why wouldn’t Matthew and Luke (and Mark and his sources) incorporate Q, M, L, and the Passion narratives, if these latter sources existed in their own right (written or oral or both)? All of this coheres together with and corresponds to the historical context of Greco-Roman texts, which incorporated sources.
17. What does all of this mean to the Church of all denominations?
The Church should reply to the charges — or at least not fear them — that Q embodies pure and original Christianity, and it does not teach the crucifixion and resurrection, so these doctrines are later (mythical) additions. In reply, the Passion traditions are earlier than Q. Also, Jewish-Christian communities in Israel were not isolated. They shared their beliefs. Q indeed is aware of the death of Jesus and says he will return like flashes of lightning. Return implies death by crucifixion and the resurrection in an early Christian context. Finally, the communities in Israel were not limited to Q. They knew about and celebrated the passion and the resurrection. The evidence throughout the New Testament and in other early sources demonstrates that these two traditions were deeply ingrained in all of earliest Christianity.
No one needs to be afraid of big bad Q, but there’s a problem with it as it relates to the Church. Scholars extract verses out of the integrated stories of Matthew and Luke to compile Q. This extraction atomizes the two Gospels. I get the impression that Q specialists are not all that concerned or sensitive to integrated stories, which are how all four Gospels now stand. I concede that studying these tiny, ripped-out fragments making up hypothetical Q may be a valid academic exercise; and Q may (or may not) have some sort of narrative framework on its own.
However, I hope we will not lose sight of the big picture. Though this article or series is not about inspiration, readers may uphold the doctrine; if so, then narrative is how and what God used and intended to communicate the life story of his Son in the four Gospels. And we can have no doubt that they exist. They are not hypothetical.
Sensitivity to full, flowing stories – not speculation about disjointed shreds – is what’s needed.
In my opinion, it is best to read the Gospels in their final form, not in small, out-of-context pieces. It is best to read the Gospels as integrated stories that were intended to report things as they really happened, miracles and all.
But at least written documents existing prior to the synoptic Gospels secure the Jesus traditions.
Articles in the Series
7. What Is the Q ‘Gospel’?
Church fathers and the authorship of the four Gospels
Reliability of the New Testament Manuscripts (Part 4 is the summary)
References and Further Reading
I recommend the linked books and articles, particularly those with double asterisks.
John S. Kloppenborg. Q Parallels: Synopsis, Critical Notes, and Concordance. Polebridge, 1988. This is the simplified reference of the Q sayings, but it is still very technical.
James M. Robinson, Paul Hoffman, and John S. Kloppenborg, eds. The Critical Edition of Q. Fortress, 2000. This is the definitive edition
F. W. Burnett. “‘M’ Tradition.” Dictionary of Jesus and the Gospels. Eds. Joel B. Green and Scot McKnight. Intervarsity, 1992. Pp. 511-12.
** D. A. Carson and Douglas Moo. An Introduction to the New Testament. 2nd ed. Zondervan, 2005. Pp. 98-103.
James D. G. Dunn. Jesus Remembered. Vol. 1. Eerdman’s, 2003.
Mark Goodacre. The Case against Q. Trinity Press International, 2001.
J. B. Green. “Passion Narrative.” Dictionary of Jesus and the Gospels. Eds. Joel B. Green and Scot McKnight. Intervarsity, 1992. Pp. 601-04.
** Donald Guthrie. New Testament Introduction. 4th ed. Intervarsity, 1990. Pp. 163-208.
K. Giles. “‘L’ Tradition.” Dictionary of Jesus and the Gospels. Eds. Joel B. Green and Scot McKnight. Intervarsity, 1992. Pp. 431-32.
Stephen Hultgren. Narrative Elements in the Double Tradition. De Gruyter, 2002.
** Eta Linnemann. “The Lost Gospel of Q: Fact or Fantasy?” Biblicalstudies.org.uk. 1996. Her article, like her other work, is hard-hitting.
** Mark D. Roberts. Can We Trust the Gospels? Crossway, 2007.
** —. “What Sources Did the Gospel Writers Use?” September 2005. Get the book and read this short blog entry for a good summary.
G. N. Stanton. “Q.” Dictionary of Jesus and the Gospels. Eds. Joel B. Green and Scot McKnight. Intervarsity, 1992. Pp. 644-50.
Etienne Trocmé. The Passion as Liturgy: A Study in the Origin of the Passion Narratives in the Four Gospels. SCM, 1983.
Edited anthologies have a wide range of perspectives:
Bruce Chilton and Craig A. Evans, eds. Authenticating the Words of Jesus. Brill, 1999.
Richard A. Horsley, ed. Oral Performance, Popular Tradition, and Hidden Transcript in Q. Semeia Studies. Society of Biblical Literature, 2006.
David E. Orton, ed. The Synoptic Problem: Studies from Novum Testamentum. Brill, 1999.
James M. Robinson. “A Written Greek Sayings Cluster Older than Q: A Vestige.” Harvard Theological Review 92 (1999) 61-67.
Petros Vassilidies. “The Nature and Extent of the Q-Document.” In Orton, pp. 138-62.