Most people from Muslim culture I know follow some of the customs, but are not really religious. Meaning they don't practice it. So they don't drink alcohol, but they don't pray either. That's why I was asking about culture.

Of course there are many religious Muslims and Christians, but because I don't care about it that much and faith is a private thing, I don't really come into contract with it. I don't go to church.

About circumcision - if religious (I would say more cultural), it's widely practiced in Judaism, Islam and even some eastern orthodox and coptic Christian sects. While I don't particularly endorse it, I don't come into contact with it while traveling.