In your opinion what causes christians to believe in Jesus

[Ivan Denisovich]

Constructing faiths which posit an afterlife is not a uniquely Christian thing. That indicates to me that positing an eternal afterlife is a selling-point for those faiths.

I'm not sure this helps your argument, because a selling-point does have to be unique in order to sell. So if the vast majority of the planet already believes in an afterlife of some kind, then there is nothing particularly unique about the belief in Christianity that voids the fear of death.

I agree that there is nothing particularly unique in christianity but geography plays a role here too. People born in Italy learn about christian take on afterlife first and ones born in Saudi Arabia learn about what islam preaches first. Other perspectives come later if at all. Uniqueness does not enter into play just simple factor of where on was born.