5 Answers

It’s a gift from God. It’s called FREE WILL

I can only speak for myself; to speculate on someone else's core beliefs....no can do. 

It has to do with upbringing and genes. If someone is brought up in a strictly religious household it is likely that he or she will also be religious though some will follow an entirely different path. For instance some of the children of Fred Phelps ( Westboro Baptist Church) have followed his example though others have rejected his views entirely. It has also been shown that religious beliefs are related to genes, so if you have the Vmat2 gene you are more likely to be religious.

I never found a religeon, science and/or phylosophy that I could not find value in it. I like all religions

some are more disagreeable than others, but all of them have something to offer.    

My son, raised Catholic, in college would say that he was an atheist, but I know he still believes.