In the context of criticism of the Jesus Seminar, it has been claimed that the actual Gospel accounts are of high reliability, and further that no Christian who reveres Christ would dare “make anything up”.
Such a view is a faith view, not the view of a historian.
First, we know that Christian scribes frequently amended the texts of the canonical gospels. We know this beyond all doubt from the literally thousands of variant Greek manuscripts which exist to this day . It is not a matter of speculation, but of observation that some Christians made stuff up.
One might argue that such glosses and “corrections” and emendations were minor. However, it appears that the story in John’s Gospel of the woman caught in adultery is, from manuscript evidence, not an original part of John’s Gospel. But perhaps it was a independent tradition that found a home there.
Fine, what about Christians making up whole books? There are several collections of these in the book stores now. Christians wrote Gospels by the scores! I would just mention two of them which are probably earlier than the rest of their fellows: The Infancy Gospel of James and the Gospel of Thomas. These are either real history or they are made up–which is it? There is the possibly early fragment from the Gospel of Peter. whose account of the resurrection cannot be reconciled with that of the canonical gospels. How about pseudo-Matthew in the 6th century who added details to the birth narrative in canonical Matthew based on his reading of Isaiah.
So far, I have shown conclusively that Christians did make up many stories about Jesus and call them Gospels and that Christian scribes felt free to adjust the canonical Gospels according to their own views, but what about the original Gospels in their autographs? Would Matthew, Mark, Luke and John make stuff up?
The historian knows that the prevailing evidence is that the canonical Gospels circulated without titles until the latter half of the 2nd century. Although the fathers quote the gospels, they never give them names before about 180 AD. So let me rephrase the question. Would the anonymous authors of the canonical gospels make stuff up?
The fact of the matter is that they did as I will show below.
Most of the Gospels consist of groups of sayings (pericopes) stitched into a narrative form, but in the birth and passion stories, we have events which purport to be as they actually happened.
Mary, a resident of Bethlehem, gives birth to Jesus. Jesus is threatened by King Herod (died 4 BC) who orders all infants in Bethlehem killed (an event not recorded in history). Mary, Joseph and the baby flee to Egypt where they stay until after the death of Herod who is succeeded by Archelaus. Mary and Joseph return and set up housekeeping in remote Nazareth because they still fear Herod’s successor.
Mary and Joseph, residents of Nazareth, travel to Bethlehem because of a census during the reign of Quirinius, governor of Syria (6-7 AD). (Roman censuses were for property tax purposes and people did not travel to their birthplaces.) After Jesus’ birth, he is presented at the Temple and then they all go home to Nazareth where Jesus grows up.
Now either Jesus was born before 4 BC or after 6 AD. Not both are possible. Either Mary and Joseph were originally residents of Nazareth or of Bethlehem, not both. Either they fled to Egypt or they did not.
These two stories cannot be reconciled with each other nor with the other known historical facts.
Or what about the synoptic Gospels vs John?
Either Jesus taught in short pithy sayings and stories (Matthew, Mark, Luke) mainly about ethical topics and the kingdom of God OR he taught in long theological discourses mainly about himself and the significance of his mission (and almost never mentions the Kingdom of God). Not Both.
Either Jesus’ ministry was carried out in one year (M,M,L) or it was more than two (John). Not both. Either Jesus was executed on the 14th of Nissan (John) or the 15th (M,M,L). Not both.
Either Jesus overturned the tables of the money changers in the temple at the outset of his ministry, and with little consequence (John) or this happened at the end of his ministry and precipitated his arrest and execution (M,M,L). Not both.
If someone wants to say that the stories must nevertheless be historically true on the basis of faith, let them say so — but that person has no credibility to make “historical” judgments on the works of others.
[Note: I would not want to mislead someone reading this page out of the context of my entire Web site. This page is only written to oppose certain critics of liberal scholarship. Questions of scholarship aside, the Gospel stories are the center if my faith and of the Church. They are true, however they came to be written, and whatever their relationship to historical dates and details. This is best summed up by the Catholic theologian, Hans Küng, who wrote:
…Of course no serious scholar assumes today, as people did at the beginning of Gospel criticism, that the disciples deliberately falsified the story of Jesus. They did not arbitrarily invent his deeds and words. They were simply convinced that they now knew better than in Jesus’ lifetime who he really was and what he really signified. Hence they had no hesitation in following the custom of the time and placing everything that had to be said in regard to him under his personal authority: both by putting certain sayings into his mouth and by shaping certain stories in the light of his image as a whole. [On Being a Christian, p 154]
 Metzger, Bruce M. The Text of the New Testament: Its Transmission Corruption, and Restoration, 3rd ed. Oxford University Press, 1992.