Need help, essay common app

I chose to do the Prompt 3 (Challenging a Belief) for my common app essay and I chose to talk about how I grow up in a family where religion is important and how I chose to become atheist but still very open mind about the belief of others.
A friend of mine told me that it’s a really bad idea and it’s not something that colleges want to read about. I’m a international student so I don’t have any counselor or teacher who knows about this stuff so I’m asking here,thank you in advance if you take the time to answer me!