That is not entirely correct ... lots of people do some real soul searching, and investigate/research ... and as a result they change from the doctrines introduced to them ... plenty examples of it. I'm one that has undergone that, and am convinced in God, and who He is. I'm also convinced that most people who don't believe are looking at the actions of man ... and trying to simplify things in their heads and blaming it on God. That would be like blaming the person who stocked a fingerling in the river for the fish that didn't take your bait ... it's honestly hilarious ... focus is all wrong.