Which, while true, doesn't make it morally right to physically bar a sinner from attending worship. I don't think it says that in the bible. So I don't think the bible is fairly clear on that.
Perhaps a quote to back up your assertion? I don't think you can find one.
Bible quotes aside, why is it wrong for a private group to be able to choose its members? Isn't this simply "freedom of association"?
Maybe you should read the two posts above where it is conclusively shown that the bible says exactly that for a Christian actively engaged in sin who defies the call to repent.
That is a different situation from someone who is not a Christian.