What they actually teach is that god allows Satan / sin / wicked people to gain ascendancy as a sort of corporate punishment for a national "turning from god".

The concept of national / tribal / family / group guilt is rather unique to Christianity so far as I'm aware, and I think many of us unbelievers fail to appreciate it, given that it just doesn't compute and we're not aware of the teaching. Intuitively, each individual has their own freedom of choice and their own responsibility for real or imagined harms they might bring about. But in the twisted world of the Abrahamic faiths, god doesn't just judge the fealty and conformance and rightness ("right"eousness) of individuals -- he judges families (visits the sins of the fathers on the children, as far as the 7th generation), tribes and nations, too. It's sort of the Christian version of karma, applied up the chain of command. Except that it's mostly bad karma. Sure, it's mentioned that "blessed is the nation whose god is the Lord" but it's mostly stick and very little carrot.

So as the Bible says, because of this "god gave them up to vile passions", "them" being "those others who don't believe like we do".

So Satan, as the prince of darkness (and his 2nd cousin, Phil, the prince of insufficient light!) are just allowed to roam around devouring who they will, because the threat of that keeps people in line. Satan is not, of his own volition, punishing people for being disloyal to his enemy.

Satan does Not punish you, your gawd abandons you to him/hell. Put the onus where it belongs, please!

They are very much misguided. This is just something that they make up so you don't stray.