Pure ignorance....its so sad its not even funny.
Short story below about how a friend of mine became an athiest VVVV
There was this dude in my unit operations class, 34 yrs old blah blah...cool dude used to always hang out with me and I would let him copy my notes from class etc etc etc. So one day we are in class talking about pumps, which goes into vacuums, which goes into black holes, then into alternative dimensions (Really cool convo). After class im walking to my car and this dude walks up to me asking me if the things we talked about made me question my belief in god. When i told him i didn't believe in god he looked at me like i said i killed mufasa....
Dude went on to talking like a girlfriend i just broke up with. Telling me that there was no way I could be atheist because im always in a good mood, im helpful, entertaining, and i drop gems constantly. Told me how they portray atheist to be devil worshipers and all this and that in the church. Shit had me baffled.
So time goes on and dude just comes and randomly asks me these probing questions. After a while i just realize this dude is looking for direction...and instead of giving him definite answers i just pointed him in the direction of research materials and good books.
Dudes a stone atheist now, and hes in a much better place than he was before....