I would like to point out that I am not knowledgeable in the Christian religion (or any religion for that matter), so excuse me if I say anything that reveals my ignorance.
Of course, Nietzsche was not entirely fond of altruism. Despite this, I remember he said that the idea of altruism that is currently held is not actually a traditional Christian thing. In fact, he said that St. Thomas Aquinas would not have agreed with the current idea of altruism (i.e. that one should do something for another, without any gain to themselves). I can't remember where I read that, but if someone could let me know where that's from, then I would appreciate it. Or if anyone has any thoughts, then that would be nice too.