My dad's a non-believer (my late grandma's a Buddhist) and my mom a Catholic. They've been happily married for 31 years.

When you're in a relationship, it's all about you and your partner, not the religion. God wants you to accept and believe in him, not to force you to convert into a religion you don't want to believe in.

Talk to him again and I hope one day he'll understand.

Good luck!