Because its brainwashing at its finest that is purposely taught to u before u establish critical thinking ability. It also uses fear mongering tactics to scare followers into believeing they will be punished in hellfire for all eternity if u even dare question it....the biggest thing i always ask myself, and religious people, is if you were born without ANY religion and at the age of 18, all of the representatives from each major religion had to present their case to you, which religion would u choose and why? What makes any religion any more truthful than the next?
Also, i'm not one of those guys that says "God absolutely does not exist" because thats just as stupid as saying "God absolutely DOES exist"...at the end of the day, i don't know and neither does anybody else because nobody ever died and came back to tell it...Also, if there is an all knowing, all powerful, and all FORGIVING god, I imagine he would be intelligent enough to see that i'm just a mere human and have trouble grappling with some of these issues as none of them really make logical sense....hell, there's even the story in the bible of dude who says he won't believe Jesus is the son of god until he can see the wounds on his hands and feet....and when jesus appaears, he repents like "my bad" and is forgiven on the spot so, why is he the exception to the rule?