Religion maneuvers it's members through the Bible. How many Christians have actually read their Bible from cover to cover? Getting educated on what is actually in the Bible can also awaken a sleeping mind. Once you become familiar with scripture that is not so nice, you begin to form doubts.
One of my friends is Catholic and one agnostic bordering on atheism. I showed them...
Ezekiel 20:23: There she lusted after her lovers, whose genitals were like those of donkeys and whose emission was like that of horses. - NIV
They were shocked that this was in the Bible. My Catholic friend said "I never knew that was in the Bible."
I told them I have a few more scriptures if they were interested. My Catholic friend was not. Uh huh.