Why are Matthew, Mark and Luke so alike? The synoptic problem

The passages

Forasmuch as many have taken in hand to set forth in order a declaration of those things which are most surely believed among us, Even as they delivered them unto us, which from the beginning were eyewitnesses, and ministers of the word; It seemed good to me also, having had perfect understanding of all things from the very first, to write unto thee in order, most excellent Theophilus.

Luke 1:1-3

The problem

Matthew, Mark and Luke can be set in columns and compared. About 90 percent of Mark appears, often word for word, in Matthew, and more than half in Luke. Matthew and Luke share about 230 verses, mostly sayings of Jesus, that are not in Mark. Each Gospel also has material of its own. The agreement in wording and order is too close to be coincidence or independent memory. John, in contrast, is quite different.

This matters for the question of eyewitness reliability. If Matthew copied Mark, he was not independently recalling the same scenes. Luke says plainly that he is using earlier accounts.

What believers and scholars say

Markan priority with Q. The most widely held theory is that Mark wrote first, and that Matthew and Luke each used Mark and a lost collection of sayings, called Q (from German Quelle, "source"). Streeter set out the classic argument in 1924. Q has never been found, but many scholars find that it best explains the agreement between Matthew and Luke.

Markan priority without Q. Goodacre and others argue that Luke used Matthew as well as Mark, which makes Q unnecessary. This view has gained ground in recent years, and it avoids positing a lost document.

Matthean priority. The Griesbach or two-Gospel hypothesis, defended by Farmer, holds that Matthew was first, Luke used Matthew, and Mark abridged both. This was the common view before the nineteenth century and keeps a minority of supporters.

Oral tradition. Some scholars emphasize that stories about Jesus circulated by word of mouth, which accounts for some of the similarity without literary copying. The word-for-word agreement over long passages suggests that writing was involved.

Where this leaves it

Almost every scholar agrees that the three Gospels are literarily related, and that the authors did not simply write down what they saw. For some, this shows how the Gospels were composed from tradition under inspiration. For others, it lowers the claim of direct eyewitness testimony. The relationship is a fact; its significance is a question of theology.