I would like to ask, need opinions... I know why I came onto this site and what I am looking for. If people send me messages or ask me to be friends and I don't want to, surely I don't have to. I really don't want to be rude, but I am serious about my faith and about what I am looking for and don't want to waste my time. Is it an acceptable behavior to not reply to the messages from non-christians? Not accept them as friends etc? But even christians sometimes send messages that tell me they will not be the one for me, so I don't reply...

Wouldn't be rude or anything, just means you don't wish to speak to that person.

Nothing is as good as knowing what need.
Truth is, you never came here to please anybody but yourself.
Your faith is still paramount.

I usually reply to all messages, but that is just me. I think it is polite to answer All mail unless is something Rude are out of the ordinary.

it's really up to you.

If you only want to date to Christians that's fine. But know that your search for a mate will be that much harder because you wont date non-Christians.

Glad to know I am also on the right track by not responding to everyone who contacts me.

God doesn't straight up tell us not to marry or "be with" a non-believer, but he does warn us about it.

2 Corinthians 6:14
14 Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness?