"Give me all of your money and god will cure your cancer!" obvious scam and a lie.

"Give me all of your money and god will make your credit card debt vanish" is another thing I've seen mega-church types say.

Incidentally, there's a conjecture around Christian circles I've seen that says these kinds of actions are what the phrase "thou shalt not take the lord's name in vain" actually warns against.

Not cursing, as it has become commonly associated with, but the literal act of using the lord for vain purposes. Like saying "Give me your money and god will cure your cancer"