I'd make an offer to the theist. If he's prepared to renounce his faith it's a coin toss.

Otherwise I'll save the atheist and he can count on Jesus to save him. Sounds fair to me.

I think durro has pretty much said it,

I'm not sure if the aim is to confirm the perceived biases of atheists, or to get atheists to admit that some theists contribute more to society than some atheists.

And, as you concede, it's a (would-be) provocative variant on an old dilemma. Why not one obese, thick bloke, and one willowy, highly intelligent, really fit woman?