In your opinion what causes christians to believe in Jesus

[Sheldon]

I think, in practice, most people believe or disbelieve for one key factor—relationship. This is something like a heuristic people follow on both ends. You will rarely find someone who believes God is megalomaniacal, sadomasochistic, and capriciously malevolent, as Dawkins alleges, and is also a believing Christian. And you will rarely find someone who thinks the God of the bible is merciful and gracious, longsuffering, and abounding in goodness and truth, as the Bible alleges, and is also a militant atheist. 

I think there is a genuine correlation there: For every Christian that says they prayed and were heard, there is an atheist saying they prayed and weren't. The Christian will say God exists because good has happened to them, the atheist will say God doesn't exist because evil happened to them. In other words, the kind of relationship you have with God spills over into a judgment regarding his existence.

Atheists - by definition - don’t have a relationship with God.

But Christians don’t believe in God because their prayers are ‘answered’. They pray for answers because they believe in God.

Boru

Exactly, and when that tornado swing away from their town, and kills every man women and child in another town, they rejoice at the infinite mercy of the deity they imagined caused this "miracle". 

There but for the grace of god go I...or more accurately, there by god's grace goes somebody else.