Deuteronomy 12:31: You must not worship the LORD your God in their way, because in worshiping their gods, they do all kinds of detestable things the LORD hates. They even burn their sons and daughters in the fire as sacrifices to their gods.
Deuteronomy 18:9-12: When you enter the land the LORD your God is giving you, do not learn to imitate the detestable ways of the nations there. Let no one be found among you who sacrifices his son or daughter in the fire...Anyone who does these things is detestable to the LORD, and because of these detestable practices the LORD your God will drive out those nations before you.
And every time someone sees something they don’t like, instantly they become Old Testament.
That’s the ticket. Don’t bother with using what that pesky Cross did. God hates that kind of innovation.