The school of Bultmann took as its departure point the assumption that in the Christian communities during the first century of our era—since the community itself in the collective would have been patently unable to act except through its individual members—anyone at all could revise or alter the basic message accepted in the community, including the words reported to have been on the lips of our Lord himself. Indeed, anyone at all could improvise or invent his own version of the Gospel, his own parables, his own teachings; and the community, in the midst of which they lived, was supposed to have been totally accepting of whatever changes or alterations they might happen to have come up with. This assumption seems highly unlikely on its face, especially considering the respect with which the average Jew treated the sacred Scriptures. It is well established that no one had the right to alter in any way whatsoever the sacred writings that had been handed down.
It will be replied, of course, that there were not as yet any Christian Scriptures to treat with respect. But that is precisely the point that remains to be proved! Even if we accepted for a moment the hypothesis that there was a long tradition of oral preaching before our existing Gospels were finally set down in writing, we would still have no evidence or indication that the early Christians permitted members of their churches to alter or manipulate or change the message regularly preached to them concerning the words and acts of Jesus. It is quite unlikely that anyone was permitted to add to or take anything away from the basic message that was known to all. What we know for certain about the earliest Christian churches, we know mostly from the Letters of St. Paul. And St. Paul wrote that “I received from the Lord what I also delivered to you” (1 Cor. 11:23). It is more than probable that this rule of the rabbi Paul was the rule observed throughout all the churches in the Mediterranean basin. The hypothesis put forward by scholars that there was a period of “creative evolution” during which numerous “literary transformations” took place which were ultimately incorporated into the text of the Gospels as we now have them is a highly fanciful hypothesis. There is no real objective or scientific basis for this hypothesis. It contradicts everything we know about the Judaism of the first century. The founders and members of the very earliest Christian churches were, at the outset, all Jews who came out of the world of the synagogue. That all these practicing Jews were suddenly transformed when they adopted the good news of Christianity, and henceforth allowed members of their communities to embelish or elaborate upon the basic message as they pleased, inventing a parable here, or a new miraculous episode there, is an improbability of the highest order.
Claude Tresmontant, The Hebrew Christ, σελ. 202, 203.