C.S. Lewis discussed this in the first chapter of Mere Christianity. Not anything related to religion (so much), but he discusses the varying vantage point on morality and the expectations that we have as humans. What one may view as one's vice may in fact, to another, be a form of salvation. Plus, we all have these false, pretentious, and hypocritical "inner-man" forms of self-proclaimed morality.
The example he used was, "Country A makes a treaty with Country B. Country B then breaks the treaty after some time, saying that the treaty was unfair. Country A and Country B then make a new treaty, only for Country A to break the treaty claiming it as unfair. Despite the fact that Country B had already done the exact same thing, they immediately get pissed because the "fair" treaty was broken." It's all relative.