it is impossible for a Christian to be altruistic because of his theology.
Jhn 15:13
Greater love hath no man than this, that a man lay down his life for his friends.
Not to mention all the commands about self-denial, dying to self, loving your enemies, doing good to those who persecute you, doing the extra mile, making yourself a living sacrifice, loving your neighbor as yourself and so on
Edited by Faith, : No reason given.