...there is no way they will give up belief in God and the Bible
I'd encourage them to question everything. If they're questioning the authority of the GB, why stop there? Go further and question the bible that these old guys say their authority comes from. Question the god they say exists. And if a person isn't willing to question that far I'd have to ask,"why not? What fears are they holding on to?" Truth will always be truth- such is the nature of truth. The GB didn't pass the truth test after we flipped them over and saw the other side and we left them. So, I think ANYTHING, even the bible and god, should be left if they don't pass the truth test. So test them out, see and understand what's on the other side
social aspects of the church
As everyone else has already mentioned, there are plenty of social and volunteer groups to be a part of without religion. In this day and age it's not hard to find a cause you care about that you can join in supporting, or a hobby group where you can meet like minded people. These things can satisfy social needs. If someone just HAS to go to church specifically, I'm sure I'd be the last person they would talk to about which one to attend. I would try hard not to facepalm if someone tried to say they go to church only for social reasons, especially if they've never tried to join a cause or a hobby group. I'm sure someone who HAS to go to church specifically is looking for more than just friends.