Jesus' Post-Resurrection Teachings and Gnosticism

The only ancient documents that speculate much about Jesus' post-resurrection teaching are the Gnostic gospels, written one to three centuries after his death. Gnosticism began in the second century AD; it was a religious system that incorporated beliefs from many religions, including Christianity. However, its basic beliefs about God, Jesus, and salvation were incompatible with the message found in the New Testament. The solution that many Gnostics found was to write their own accounts of Jesus' teachings in which Jesus sounds more like a Gnostic. In order to seem more authentic, these gospels were falsely attributed to people like Judas, Thomas, Mary Magdalene, Philip, Peter, and others. In many of these gospels, these Gnostic beliefs were only communicated by Jesus secretly to a few of his disciples in the days after his resurrection.

So it is probably a mark of the genuineness of the NT accounts that they do not record any post-resurrection teaching of Jesus that is fundamentally different from his earlier teaching. Jesus had already taught about his coming death and resurrection, the founding of the church, and his return; after the resurrection, he added little (for more on these themes, see posts here and here). Perhaps Jesus did not need to to add much; after all, almost everything that the apostles wrote about is a development of these three themes.

The picture above shows Jesus appearing to Peter and John; it is found in a book entitled Das Plenarium oder Ewangely Buoch (a set of gospel readings for masses), published in 1516.