I'll be frank, I've never really gotten the deal with the seven deadly sins. I always thought, dunno, hurting people, killing people, theft, rape, etc. were the bad things ... but no, the things that get you condemned to hell are thought crime. Thinking bad thoughts is worse than doing bad things, because you might be doing bad things for a higher cause - like because God or an infallible Pope told you to do them.
Mea culpa, mea maxima culpa, I did not know better, I am fallible, and thus I thought God would tell his own once we slaughtered all these potential heretics.
Of course, I don't mean to single out any particular religion here. The last half-century has furnished us with plenty examples of other religions, from Communism to Islam, which have gotten up to terrible things in the name of a higher cause. And still a bit of lust is considered a deadly sin. Huh.