Holy crap, this has gone way farther then it should have. But because I'm missing the fun, the point isn't that he is limiting himself from anyone. He just wants to hangout with people with similar belief. Its the same as a church playing football together or going laser tag. The points not the "spread the word", its just to be with people who have similar beliefs. It also helps relax tension. For example, since its a group of christians, they may pray prior to games. If your atheist, you may be offended by this. In fact, its kind of a conscious thing. He doesn't want to offend any one. Thats why he wants a group secluded towards christians.