Unitarianism is a term that describes some forms of Christianity. Unitarianism can be described as the belief that God is just one person. This is different from what most other Christians think, which is that God is three different people all in the same person. That belief is called Trinitarianism. Unitarian Christians believe in Jesus of Nazareth. They think that Jesus was a great leader and prophet, but they generally do not think that Jesus is part of God himself.