You've actually hit on the main functional mechanism to manipulate people. That is, a great many people want to be "good", so the "authorities" simply instruct them as to what a "good" person says, feels, and does. Following those instructions is--definitively--being "good".

This is not the way a person with normal moral function works. That person tries to determine what is moral, then speaks, feels and acts accordingly, without regard for the opinion of the "authorities" or anyone else. The strongest of such people are willing to endure punishment for the sake of morality.

These can be hard to distinguish if you're not looking closely, but it's like two sides of the same coin: extremely close but entirely opposite and with a world of difference. Almost everyone assumes everyone else is like them. They are not.