I want to read about Hindus, Buddhists, Muslims, Jews, and Sikhs. I want to read about people who grew up in a culture fundamentally different than my own, which was molded by their religion. Faith is obviously a big factor in many people's lives, and I think we, as writers, should do a better job of honoring that. From what I can tell, books are getting slightly more religiously diverse, but not by much. If you're committed to this, it can greatly expand your worldview, and will give readers something new, that I believe publishing still needs today. How does one write about a religion whose beliefs s/he isn't familiar with, without appropriating the character's culture?
1. Do extensive research. Read their sacred scripture(s) if possible, and study the religion's history.
2. Figure out the culture around their religion. Do people dress modestly? What do they talk about? What are their values? What separates them from similar religions or people? What's their daily life like? How much is their faith ingrained in their life?
3. Find blogs written by people actively practicing their faith. See if there's a place of worship anywhere nearby that you could visit for a service, if they're open to guests.
4. Talk to at least one person who is a believer about their religion. Make sure that your biases don't distort the information you get. Also, remember that it's only one person's view, and so that varies highly.
5. If possible, find someone from that religion who would be willing to read the book once it's ready to make sure it's an accurate representation of their faith.
If you have any other tips or suggestions for books with non-Christian main (or even side) characters, I'd love to hear them in the comments.