In the best case, it's a form of harmless self-deceptive delusion. One step after that, it mostly harms the person engaging in it. In its most malign form, we all know what it leads to.
Discussion
I concur. And I have always found extremely creepy when religious people imply that they behave according to certain socially positive rules, for instance, the so called Golden Rule ("Treat others as you'd like to be treated yourself"), either out of fear of divine retribution, or as a means to get divine reward. That's basically a sociopathic calculation, rather than a virtuous one.