As far as I'm concerned, a "non believer" is one that doesn't believe in God.
I think a non believer is one who doesn’t or can’t think. I think most people equate belief with God. One doesn’t have to believe in God but everybody believes in something or someone.
As for the JW's, a non believer is someone that doesn't believe 100% of what the Watchtower says, no matter if there were flip flops on many subjects.
Go to any cult and they will say the same thing. Wouldn’t it be great to gather all these cults who believe they are the only way and have them in a debate together.
I find it insulting when a JW will consider a member of another religion that prays ,and who may devote lots of time helping people, like Jesus said to do, and still be branded a "non believer", no better nor worse than the worst scum of society that may be in jail for murder.
I don’t find it insulting anymore. Last November my mother was really upset over something and I asked if we could pray together. She was aghast and said "but we pray to Jehovah". It was such a slap in the face and I asked her who she thought I was praying to. I am now just saddened that she doesn’t have the truth. I am confident that I am praying to the right God.
As for the last comment I understand and believe it in a worldly way too, but to God all sin is something that separates us from God. Even the murderer, if he is truly remorseful, can be forgiven. We are saved by grace. (no not by the previous poster-sorry Mouthy-couldn’t resist)