Don't just say "I realized it was all a bunch of stupid fairy tales". How and why did you come to that conclusion? Was there a specific event or series of events? Here are some things for consideration...
- Was it scandal, hypocrisy, and corruption among the ministers or your coreligionists? Was it the past sins of or evils committed by it? Was it the presence of seemingly unchecked evil in the world?
- Were you pressured by friends or family members? Was it the loss of a friend or family member (death, separation, divorce, "falling out", etc.)?
- Were you overwhelmed by personal sins of which you felt you couldn't be forgiven? Did you simply not understand your faith? Were you poorly educated on it?
- Did you ask for something in prayer, but it was not granted to you?
- Did you become too busy with work or school? Was it leaving your home environment for the first time and not having the same community or support system that you had before?
- Were you upset because it wouldn't embrace your view of the culture ("get with the times", "modernize", etc.)?
- Did its texts contradict itself, nature, etc?