I think the old adage it true however, “you can’t cheat an honest man”.
One variety of con is called the "pigeon drop" and that plays on human greed. However, the "pigeon drop" is not the ONLY con.
You can make as much money playing on a man's concern for the safety and welfare of his children and family. That is, you can rip him off by tricking into believing he is being altruistic.
That's what the phony insurance business is about.
The fellow telling folks "you can make the tithe even if unemployed" was preying on "newbies" ~ folks who'd only had enough information about tithing standards and customs to be dangerous to themselves.