Dora Bas Rivka Silver O'H
I'm Not Naming Any Names Here, But...
God's going to drive out the Canaanite nations and the Jews should not make the mistake of trying to emulate them. They are not to inquire as to the religious practices of these nations with the intention of experimenting with them. God drove the Canaanites out for a reason and He doesn't care for their manner of worship, which went as far as human sacrifice! Just do what God says; He knows what He wants from us, so don't think you can improve things by copying other nations' ways!
There will come a time when someone arises from among the Jews who may be able to do signs and wonders. Based on those miracles, he will try to change the religion and innovate new forms of worship. Don't listen to him! It's a test to see if you'll follow God's words. The “prophet” who tries to lead the Jews down a new path has committed a capital crime.
It might happen that even one's closest friend or family member might try to proselytize him into following another "god." Don't fall for it and don't cover up for him, since he has committed a capital offense. The penalty for this is stoning.
If the nation hears that an entire city has been thoroughly led astray into idolatry, the charges must be investigated. If the accusation is found to be true, the city must be thoroughly wiped out. It is so completely corrupt that even the animals and property become forbidden for use and must be destroyed. The city must be burned and never rebuilt. And don't keep any of the property as spoils!
This is really hard to do. It is - or should be - completely antithetical to human nature. Such actions run the risk of desensitizing people, so God assures the Jews that if they do these difficult things when they are necessary, then He will reinforce their attribute of mercy to keep it from affecting them adversely. He assures us that these are the right things to do, albeit in ways that we can't fully understand.