Religion or not, faith or not, it's all really personal choice.
I can actually say I don't masturbate. Really and honestly, I can say that. But not because of my beliefs in God and the Bible- not because I feel it's immoral. It's a very personal choice, though. Just like many things revolving around sex.
Beliar:
I'm glad I'm not alone in that opinion. By all means, I don't care if others masturbate. I don't find it immoral, I don't believe they're sinning. But I find the idea disgusting and would rather be with another person. So I don't masturbate.