Your question concerning the accuracy of the Gospels is an interesting one. Among divinity scholars, the predominant opinion is that the Gospels were in fact not attempting to create an accurate historical portrayal of Jesus. They were not claiming to be eye witness accounts. The Gospels were a means of interpreting the life of Jesus theologically. Early "readers" of the Gospels (who would probably have heard the stories read aloud in Church rather than reading it themselves) likely interpreted the stories allegorically rather than literally. They were not looking to know the facts of a historical figure's life; they were looking for lessons on how to lead a moral life.
Matthew, Mark, Luke, and John were each writing for an audience at a particular point in history. Each of them alter the story of Jesus's life slightly in order to adapt it for their community of readers. This again puts into question the idea of accuracy: Matthew alters Mark's account to adapt the story of Jesus to his theological view of the world.
In accordance with what has been previously written, each apostle wrote his gospels to different audiences with different purposes. For instance, St. Matthew wrote to the Jews in order to prove to them that Jesus was, in fact, the Messiah for whom they had been waiting; St. Mark wrote to a Gentile audience, making his argument that Jesus is the Son of God by focusing on the life of Christ; St. Luke's intentions were to record the historical account of the life of Jesus; and, St. John's Gospel is a reflective, theological account of his time with Christ. Theologians assert, therefore, that the Gospels are so different because of the audiences and purposes of each apostle, not because of content inaccuracies on the part of the writers.
While skeptics have claimed that there are many errors in the Gospels, there are strong arguments to the contrary. For instance, Dr. Craig Blomberg, who is a New Testament scholar writes,
Despite two centuries of skeptical onslaught, it is fair to say that all the alleged inconsistencies among the Gospels have received at least plausible resolutions.
Historically, the ministry of Jesus Christ is established as from 27-30 A.D. F.F. Bruce, in his book, The New Testament Documents: Are They Reliable? 5th ed. (Downers Grove: InterVarsity Press, 1983), provides evidence that the New Testament was completed by 100 A.D., and most of the New Testament writings were completed twenty to forty years prior to this date. [Mark, 60 A.D.; Matthew and Luke, 60-70 A.D.; John, 90-100 A.D.] Because there is no more than 70 years between Christ's death and the writings of the apostles, Biblical scholars hold with the accuracy of the Gospels. For, experts state that the time between the writing of the Gospels and the death of Christ is too short for legends to have developed. Historians have long agreed that it requires two generations, or eighty years, for the establishment in a culture of legendary accounts.
Moreover, Old Testament scholars have long pointed to the Jewish tradition of memorization of Scripture. In Deuteronomy 6:4-9, for instance, the Jews are exhorted to memorize and pass on the word of God. Thus, the Jewish culture was one in which the oral tradition was revered. In such a culture, the ability to memorize and the skills of memory far surpassed those of modern people. Therefore, it is widely held that accuracy remains in the Bible. Darrell Bock, a New Testament scholar, asserts that the Jewish culture was "a culture of memory," so the preservation of the accuracy of the Gospels is assured. Interestingly, "ninety percent of Jesus' teachings and sayings use mnemonic methods similar to those used in Hebrew poetry." Since Jewish boys learned to read and write by age twelve, the apostles would have been well-equipped to record accurately the teachings of Christ. Many of His parables were easily remembered; to this day, they are tales that are easily recognized.
There is also external evidence to the accuracy of the Gospels, evidence that points to a first century date for these recordings of Christ's life, works, and words. Here are some of these documents:
- The Chester Beatty Papyri - These hold most of the writings of the New Testament and dates around 250 A.D.
- The Bodmer Papyri - These contain most of the Gospel of St. John
- The Rylands Papyri - These contain a fragment of St. John's Gospel and dates to 130 A.D.
- Dead Sea Scrolls Cave 7 - Jose Callahan located in them a fragment of the Gospel of St. Mark and determined that it had been written in 50 A.D. In these scrolls were also fragments of Acts and other epistles and dating them slightly after 50 A.D.