The thing with Christians

So well put by Sheldon Vanauken in his book A Severe Mercy:

The best argument for Christianity is Christians: their joy, their certainty, their completeness. But the strongest argument against Christianity is also Christians -- when they are sombre and joyless, when they are self-righteous and smug in their complacent consecration, when they are narrove and repressive, then Christianity dies a thousand deaths. But, though it is just to condemn some Christians for these things, perhaps, after all, it is not just, though very easy, to condemn Christianity itself for them. Indeed, there are impressive indications that the positive quality for joy is Christianity -- and possibly nowhere else. If that were certain, it would be proof of a very high order.