We have to remember that Jesus died around 30. For 40 years, there's no written gospel of his life, until after the revolt. During that time, we have very little in the way of written records within Christianity. Our first writer in the New Testament is Paul, and his first letter is dated around 50 to 52, still a good 20 years after Jesus, himself. Paul doesn't write a gospel. He actually doesn't tell us much about the life of Jesus at all. He never once mentions a miracle story. He tells us nothing about the birth.
remember that the gospels themselves and their full account of the life and death and resurrection of Jesus came a good bit after the fact, a full generation, in some cases perhaps even sixty years, two generations later. So those stories had a long time to evolve and develop.
Now here's what he tells us, he says that Jesus died, was buried, was raised on the third day in accordance with the scriptures, (how amazing) he relates it to prophecy. Then he says, "Jesus appeared". He doesn't tell us about the empty tomb. There's no reference to that part of the story at all. Instead he tells us Jesus appeared, first to Peter and then the twelve, next to 500 people, some of whom had already died by the time Paul heard the story.
The earliest quotations or words of Jesus that we have are not in our gospels, but they are in the letters of Paul. And each one of these words of Jesus that appears in the letters of Paul is advice for the regulation of the life of the community.