The Christian community will never be obsolete. It's made up of true believers. That's all that counts. It's not a numbers game except to those who want to make it so.
I think it is partially a numbers game. The Bible asks us to evabgalize and be a good Christian witness. To the extent the “numbers” are not good there is evidence of us not doing what Jesus asks us to do. Saying it is not a numbers game is like a liberal saying it is the “good intentions” in the policy that matters, as opposed to looking at the results of the policy.