In your opinion what causes christians to believe in Jesus

[Rizen]

despite not being able to proof that he existed for starters 

 And in your opinion why some of them assume that their type of relationship (its even questionable if it is their or they just obedient sub - u know usual one is sex only in marriage) is the correct one and how their view on what`s virtue vs vice is the right and universal/inherent one?

People are terrified of the unknown. It's a lot easier to say "if you're good you'll go to heaven when you die" or "this happens because god works in mysterious ways" than admit you don't have the answer. Plus people like to think god or Jesus or whatever you subscribe to is working for them. "Maybe if I pray god will answer it". "Jesus died for my sins so I don't have to feel guilty". God is like a teddy bear. It's a very childish mentality.

[The Grand Nudger]

I think that every deeply christian person has done some unspeakably terrible thing - at least in their own minds. Something that they think they can never atone for themselves. If I boarded a plane that was going to go over the andes and I found out it was full of evangelicals on a mission, I'd pop the lever and slide down the escape hatch. If I learned that fact in nasty turbulence mid flight, I'd strongly consider jumping. Not kidding.