I could have been knocked over with a feather the other week, when a friend started a local homeschool group (while I was gone for a few weeks) for secular homeschoolers. Her religion (particular form of Christianity -- but she never judged others, thankfully!) was very important to her, she viewed it as beautiful, etc. She said that one day, she just suddenly realized, the bible is fiction! Then she saw how the usual arguments the xians use are circular -- using the bible to support the bible...
We live in an area of the country where, especially as homeschoolers, the fundies are the dominant force (though gradually that has been changing.) I was just relieved that the change in view occurred because of her thinking about things, rather than some crisis. (She's had a number of them in her life, so I was worried about her health.)
Her son still believes -- she didn't feel like she could just take it away from him, tell him, okay, everything I've taught you these last 13 years is wrong! -- but I figure if he has an environment where he can question and think, he will be fine.
The biggest downside she has found is that former friends from her church are snubbing her, lying about her, cheating her -- and feel they should be absolved because they confessed. No restitution made, just confessed. Sigh.