The short answer is this: it’s okay to discuss religion in your essay as long as the take-away (or values) promoted in the essay are universal. Here’s what I mean:
Posts by Ethan Sawyer, the College Essay Guy:
How Do I Write the “Why Us?” Essay?
1. Don’t write about the school's size, location, reputation or the weather.
Why? Because that's what half of America is writing about. Take a hint from Emory University, whose “Why us” essay used to read: