When Moses came down from Mt. Sinai he witnessed the tribes of Israel worshiping the Golden Calf. He commanded the righteous to take their swords and strike down the wicked, their own brothers and family. Killing 3,000 of their own for turning away from the Lord (Exodus 25:27-29)

How does this apply to survival? I think this is a clear example. Sometimes you must enter into evil in order to preserve and save the worthy and righteous.