The Moral Argument states:

1. Every law has a law giver.

2. There is a Moral Law.

3. Therefore, there is a Moral Law Giver.

 

Here is another way to state the argument:

1. If God does not exist, objective moral values do not exist.

2. Objective moral values do exist.

3. Therefore, God exists.

If God does not exist, then what the Nazis did was not objectively wrong. It was just a matter of preference or choice.