The Gospels have been much maligned as being copied one from another, not from independent witnesses (for Matthew, Mark and Luke) and that they were written a long time after the events, hence lack eyewitness statements. The Wikipedia page on this notes:
Although some claim that all four canonical gospels meet the five criteria for historical reliability, others say that little in the gospels is considered to be historically reliable. … Most scholars hold to the two-source hypothesis which claims that the Gospel of Mark was written first. According to the hypothesis, the authors of the Gospel of Matthew and the Gospel of Luke then used the Gospel of Mark and the hypothetical Q document, in addition to some other sources, to write their individual gospels. These three gospels are called the Synoptic gospels since they are all very similar.1
Dr Floyd Nolen Jones responds to claims like these in an article2 “The Gospel Colophons.” In the following I reproduce it in full.
Because the first three Gospel’s contain so much material in common that they may be arranged as a synopsis, they have been labeled the “Synoptic Gospels”. New Testament criticism alleges that:
Matthew and Luke used practically all of Mark in preparing their respective Gospel accounts,
Matthew and Luke recorded nearly identical matter for much that is not found in Mark; therefore they both used a second source in common (i.e., “Q” for the German word “quelle” meaning “source”),
“Matthew and Luke make improvements in many places”. “Matthew smoothes [sic] … introduces words he prefers”, etc., and/or
Mark wrote his gospel under the influence of Simon Peter, etc.
The above commonly appear in Biblical literature and have come to be known as part and parcel of the so-called “Synoptic problem”. To account for the similarities and differences between the Gospels of Matthew, Mark, and Luke, the critics have devised this hypothesis wherein they assert that Mark was written first and Matthew and Luke consulted his Gospel along with “Q”. Thus, these Gospels are said to be the result of interdependence among the three “Synoptic” writers. Indeed, the claim is even made by many that Matthew and Luke handled Mark “critically” (i.e., as text critics).
In 2008, Dr. Wilbur N. Pickering3 discovered colophons in numerous ancient manuscripts that contained the Gospels. Colophons are inscriptions, usually placed at the end of a book or manuscript, which normally contain the name of the owner (or scribe) and an attempt at dating the writing. Dr. Pickering states that 16-18% of the 3,000+ extant NT manuscripts (c.500) belong to the Byzantine (Textus Receptus) sub-group designated as f35 (critics subdivide the NT manuscripts into four artificial families: the Alexandrian, Byzantine, Western, and Caesarean). Dr. Pickering has 54 manuscripts (in 2009) of the f35 sub-group that contain the 4 Gospels, and he states that c.95% of these have colophons. About 1,800 of the extant MSS-mss contain the Gospels (some are fragments), and Dr. Pickering extrapolates that 50% have colophons.
Thus, approximately 50% of the 500 f35 manuscripts of the Gospel of John have “published 32 years after the ascension of Christ” in the colophons and: 30 + 32 = 62 AD, rather than 85-95! For 50% of the f35 mss to have this information implies that the tradition is ancient, and Pickering has further shown that the f35 sub-family goes back to at least the 3rd century AD. The colophons also record that Luke was “published 15 years after the ascension of Christ” (30 + 15 = 45 AD, not c.60).
The same sources have Matthew “published (or “given out”) eight years after the ascension of Christ” (30 + 8 = 38 AD, rather than c.50)! The colophons also say that Mark was “published 10 years after the ascension” and 30 + 10 = 40 AD, not c.68 AD. Now 40 AD for Mark’s Gospel is two years after Matthew, not before as the text critics would have it. Thus, not only were the four authors of the Gospel accounts of Christ Jesus eyewitnesses of the events, many others were still alive when the Gospels appeared. This would include most of the over 500 that actually saw Him [our Lord] after His resurrection (1 Corinthians 15:6). (emphasis added)
The f35 sub-group of the Byzantine family is without equal in the MS tradition – about 500 of all the 3,000+ extant manuscripts are f35. Since the f35 mss come from a large, diverse geographic region (Jerusalem, Sinai, Trikala, Mt. Athos, Constantinople, and Rome), the likelihood that they do not represent the main line of transmission is nil. Thus, beyond any reasonable doubt, the f35 Gospel colophons must be seen as valid ancient witnesses and their dates taken as absolutely legitimate. Since they testify that Mark was written two years after Matthew, the so-called “Synoptic problem” is forever slain. The critics merely have theories; we have the facts, and facts are stubborn things.
The Gospels, as well as the other books of the Bible, are clearly written as to be self-evident that the authors are portrayed as first-hand witnesses and/or direct receivers of divine revelation. By the very demand of Scripture, nothing less would suffice as a legitimate and legal testimony.