Well, it's a bit complicated when you think about it. The kid is technically harming people since in this world gods are real and do require sacrifice. Even the kind water-giving god basically causes thousands to die trying to reach its abode. On the one hand, a god that straight up demands human sacrifice is probably not a nice one and would severely punish the duped sacrifice-giver, so the kid is actually doing harm. On the other hand, being willing to sacrifice a little girl means they deserve the god's wrath.