Am I wrong for not telling my friend that I’m religious?

So I have been really good friends with one of my male coworkers. We get along great and he is the nicest person on the planet. He is openly gay and we always talk about our relationships. He recently found out through a mutual friend that I was celebrating a religious holiday, and I am actually pretty religious. Now he is mad at me because he thinks I only pretended to be his friend and he thinks I can’t be religious and like gay people. But honestly, I don’t go around talking about religion and I think we shouldn’t judge people. So him being gay was never an issue to me. Why can’t I believe in God and be friends with him? Why do I need to tell people my religious views when they only concern me and don’t harm anyone else?

(I’m not Christian)