In reply to quadding 101, I must point out that in I Sam.15 the reason God gives for killing all the Amelekites has nothing to do with their sex lives, it is because of a dispute they had with the Israelites about 400 years previously!
Even assuming that the Amelikes were sexually abusing their children – and we have no evidence from the Bible or anywhere else that they did – having them all murdered by the Israelites seems an odd sort of therapy. Would it not have been closer to the ideal of a loving God if he had healed their minds of the scars of this hypothetical abuse, then had them adopted by the Israelites?
Such moral dilemmas cannot simply be solved by saying that the murdered children all went to heaven, so really it was OK. If heaven is eternity with a God who orders the mass slaughter of children not everybody might think it a good place to go.