Oral Tradition and the Historical Reliability of the Gospels
Craig Blomberg has written extensively on the historical reliability of the Gospels. In the relevant article in the Dictionary of Jesus and the Gospels, he identifies a number of factors that support the probability that the Gospels faithfully preserve the oral traditions on which they are based.
1. Jesus was perceived by his followers as one who proclaimed God’s Word in a way which demanded careful retelling.
2. Over ninety percent of his teachings has poetic elements which would have made them easy to memorize.
3. The almost universal method of education in antiquity, and especially in Israel, was rote memorization, which enabled people accurately to recount quantities of material far greater than all of the Gospels put together.
4. Oral story-telling often permitted a wide range of freedom in selecting and describing details but required fixed points of a narrative to be preserved unchanged.
5. Written notes and a kind of shorthand were often privately kept by rabbis and their disciples, despite a publicly stated preference for oral tradition.
6. The lack of teachings ascribed to Jesus about later church controversies (e.g., circumcision, speaking in tongues) suggests that the disciples did not freely invent material and read it back onto the lips of Jesus.
7. The degree to which Jesus emphasized his imminent return, that is, to the exclusion of envisioning the establishment of an ongoing community of followers, has been exaggerated. Hence, the claim that the disciples would have had no interest in preserving the Gospel tradition until the second generation of Christianity is doubtful.