The first three Gospels—Matthew, Mark, and Luke—reveal much similarity in content, style, and expression. As a result, Matthew, Mark, and Luke are referred to as the Synoptic Gospels. The word synoptic basically means "to see together with a common view." The many similarities among the Synoptic Gospels have led some to wonder if the human authors shared a common source, such as another written account of Christ's birth, life, ministry, death, and resurrection, from which they obtained the material for their Gospels. Some argue that Matthew, Mark, and Luke are so similar that they must have used each other's writings or another common source. This supposed "source" has been given the title "Q," from the word quelle, the German word for "source."
What is the Synoptic Problem?
Is there any evidence for a Q document? In terms of an actual written document to support the theory, no, there is not. No portion or fragment of a Q document has ever been discovered. None of the early church fathers ever mentioned a Q source behind the gospel accounts. Q is a modern invention to support a human explanation of the composition of the Bible. While human authors composed these Gospels, there is no need for such an explanation. The Bible itself claims its writings are the supernatural, inspired work of God.
If Matthew, Mark, and Luke did not use a written Q document, why are their Gospels so similar? There are several possible explanations. It is possible that whichever Gospel was written first (likely Mark), the other Gospel writers had access to it. There is absolutely no problem with the idea that Matthew and/or Luke used content from Mark's account as a source for their writings. Perhaps Luke even had Mark's Gospel in mind when he penned the introduction to his writing. Luke 1:1 tells us, "Inasmuch as many have undertaken to compile a narrative of the things that have been accomplished among us." Could one of those "many" have been Mark?
A further, more likely explanation is that the common-source theory presented in Q is the result of a myriad of oral and/or written traditions already in existence about Jesus and His ministry. All three writers of the Synoptic Gospels would have known of these sources.
Ultimately, the explanation as to why the Synoptic Gospels are so similar is that the same Holy Spirit inspired them all. Further, all three Gospels were written by eyewitnesses or were based on the reports of eyewitnesses. The same basic information would have been available in all three accounts. Matthew was one of the original twelve apostles. Mark has traditionally been noted as the account of the apostle Peter's perspective. Luke was an associate of the apostle Paul, and his Gospel is based on the accounts of several eyewitnesses. Why would we not expect their accounts to be very similar to one another? Each of the Gospels is inspired by the Holy Spirit (2 Timothy 3:16-17; 2 Peter 1:20-21). Therefore, we should expect coherence and unity.
The Q Gospel – What is it? If there was a Q Gospel would that make the Synoptic Gospels less valid?
When were the Gospels written?
Why are there four Gospels instead of one?
Has the Bible been corrupted, changed, or tampered with?
The Dead Sea Scrolls - What are they and why do they matter?
Truth about the Bible