In your opinion what causes christians to believe in Jesus

[Alan V]

People understand that the world isn't perfect from a human perspective. It is changeable and incomplete and full of obstacles and problems. We all struggle and die. However, instead of accepting all of this as merely factual, we are dissatisfied and anxious. So we invent or embrace religions to try to compensate for our terrible or tedious experiences. We imagine that everything could come right someday, if it isn't in this life (through certain practices) then perhaps after death. Effectively we choose to live in our imaginations instead of the real world, since so many of us find the real world too unappealing.

Christianity is just one popular imaginary world. But like all fictions, its internal inconsistencies betray its imaginary nature.