Many people I know play Dungeons and Dragons as a hobby. I really started to think about it the other day and I realized that It played an integral role in shaping my mind to think more rationally, even though it deals with mostly fantasy aspects of fiction.
I started playing when invited and enjoyed making characters and trying out new voices and pretending to have the different attitudes of the characters I was portraying (not as serious as it sounds, just a bunch of guys sitting in a basement talking with each other drinking mountain dew all night). I actually enjoyed making new characters more than I liked playing.
But on to the main point: Deities in Dungeons and Dragons give you certain bonuses and abilities based on what class you are. If you a Paladin, Cleric or Druid for example a God is considered to give your fictional character magical power.
This changed my view of God in 2 ways. First because the Deities actually did physical things to the character in the game. There was a real benefit to having a God. Not just an emotional solace driven reason. Secondly I began to really look at the ways that my god was perceived by me as "helping me" in my daily life.
As an experiment I stopped praying and didn't tell anyone. I also stopped paying tithing and stopped going to church for a while. I found that not only had nothing changed but my fellow church members actually saw no change in my character or in me whatsoever. I did not become poor.
As a further part of my experiment (This is when I actually started being an atheist) I told specific church-going people that I was an atheist. There was a major change in how they treated me. They were colder and treated me like I was retarded. Soon they broke off all ties completely. I then told my parents and they also treated me differently in that they thought I was a terrible person who only wanted to sin.