The Israelite soldiers had taken over a city and killed all the adult men. They brought the women and children back to Moses, and Moses, presumably speaking under god's authority, commanded them to kill all the women who were not virgins and all the young boys, and to keep the little girls for themselves as war brides. This is what the Bible describes, and god never condemned it.
If an army did that today, would you be okay with that? Because that's literally what you're defending.
Also, I don't believe in God, so calling me godless as an insult is completely ineffective.