This is a thorny issue. On the one hand, we're weighting supernatural beliefs against real life-saving treatments. On the other hand, the backlash we can get

This is a thorny issue. On the one hand, we're weighting supernatural beliefs against real life-saving treatments. On the other hand, the backlash we can get from some religious people is just as real. God will never smite me, but his followers might. More generally, I'd say this is not the right way to combat religion. There are reasons why we still have religions, some of them worth copying (helping your neighbour and such), some of them worth combating (such as fear and poverty). Going directly against he will of religious people is only going to get ugly.