Evidence to Support the Two-Gospel Hypothesis

The Synoptic Puzzle Analysis of parallel passages in the Synoptic Gospels yields the following data:

The question of how to explain these relationships is called the “Synoptic Puzzle” (or the “Synoptic Problem”).

The Two-Gospel Hypothesis (aka Griesbach Hypothesis)

The following points are often cited by supporters of the Two-Gospel Hypothesis as evidence for the validity of that theory.

Evidence for Matthean Priority

The unanimous tradition of the church from (at least) Augustine until the eighteenth century has been that Matthew’s Gospel was the earliest of the four. This can be challenged only on the basis of so-called internal evidence (trying to make sense of which Gospel would be more likely to have made changes from the others). But since the external evidence unanimously identifies Matthew as first, that proposal should be the default position, unless what follows from it can be shown to be improbable (which proponents of this theory maintain is not the case).

Matthew’s Gospel is the most Jewish, apparently expressive of Jewish-Christian sensibilities and attentive to Jewish-Christian concerns. This fits best in a very early context, since the church rather quickly became a primarily gentile institution. For example, Matthew’s Gospel portrays Jesus as insisting that all Jewish laws should be kept by his followers (5:17–20; cf. 23:2) and in one instance he even instructs his disciples not to go to gentiles (10:5; 18:17 could also be read as implying gentiles are not currently part of the church).

Evidence That Luke Used Matthew

Matthew and Luke have an enormous amount of material in common (about two-thirds of these two Gospels overlap). If Matthew is presumed to have written first (see above), the simplest and most logical explanation for this common material would be that Luke used Matthew’s Gospel as one of his sources. Luke explicitly says in the prologue of his Gospel that “others” have already written accounts of Jesus. If Matthew’s Gospel were written first, it would likely have been one of the works to which he refers.

Hypothetically, Luke could have derived some of the material he has in common with Matthew from the Gospel of Mark, since much of that material is also found in Mark. However, even if Luke had a copy of Mark’s Gospel (which proponents of this theory deem unlikely), he still must have used Matthew as a source because Luke often agrees with Matthew against Mark in passages common to all three Gospels.

For example, in the parable of the mustard seed (Mark 4:30–32), both Matthew and Luke contain the words “a person having taken it,” “becomes a tree,” and “branches” (Matt. 13:31–32; Luke 13:18–19), although those words are not found in Mark. Likewise, in the account of Jesus’s abuse by soldiers, both Matthew and Luke have the soldiers ask Jesus, “Who is it that struck you?” (Matt. 26:68; Luke 22:64), words not found in the Markan parallel (Mark 14:65).

Hypothetically, Luke could have derived some of the material that he has in common with Matthew from some other source to which both Matthew and Luke had access (e.g., the so-called Q source proposed by some scholars). But there is no external evidence for the existence of such a document or reference to it in any church tradition.

Hypothetically, the material that Luke and Matthew have in common could be explained by Matthew having used Luke as a source rather than the other way around. But this seems unlikely because (a) church tradition holds that Matthew was written first; (b) Luke (but not Matthew) refers to previous accounts being written; and (c) Luke’s editorial changes to what he would have found in Matthew’s Gospel are held to be more explicable than the changes Matthew would have had to make, supposedly, in Lukan material if the situation were reversed.

For example, Luke can be understood to have split up the long teaching sections found in Matthew’s five great discourses and redistributed that material throughout his narrative; this keeps the story with a more linear flow and also serves his interest in presenting much of Jesus’s teaching with the context of a journey. It seems unlikely, however, that Matthew would have omitted many stories found only in Luke if he had known them (e.g., the parable of the Pharisee and the tax collector in Luke 18:9–14, which would fit perfectly with Matthew’s frequent denunciation of Pharisees).

Evidence That Mark Used Matthew and Luke as Sources

All but a handful of verses in Mark’s Gospel overlap with material found in either Matthew or Luke or both. If Mark had a copy of both Matthew and Luke, two distinctive types of parallels would be explained: instances in which Mark agrees with Matthew against Luke and instances in which Mark agrees with Luke against Matthew. Since Mark’s Gospel is much shorter than either Matthew’s or Luke’s, the assumption of this theory is that Mark’s Gospel was produced as a simultaneous conflation and condensation of the two. The desire to abbreviate would explain why many stories in Matthew and Luke are not found in Mark.