Anecdotally, people my age seem to be opposed to the idea of original sin. This is interesting because it has more or less been widely accepted since Christianity showed up and has probably only recently suffered a decline in supporters. However, I bet these same people would agree with the statement that humans are inherently flawed, and we need to work to overcome those flaws. Young adults may only be rejecting the idea that some omnipotent being has created them as imperfect, and are willing to accept that their imperfections are a result of natural selection or some other process. Or, they are rejecting the idea that just by existing they are sinning and doing something wrong.
What this secularization of imperfection loses, in my opinion, is the complementary idea that we should strive to become less sinful, or more perfect. If we believe that we are born with original sin, then we believe someone/thing has already made a normative judgement about our character, and expects us to improve (leaving alone whether absolute perfection/sinlessness is possible). However, if we believe our imperfections or more akratic tendencies are only biological baggage from a bygone era, then we are more likely to accept ourselves just as we are. If talking about imperfection as “original sin” gives us a spectrum from sinful to sinless to work with, then talking about undesirable tendencies simply as personality traits gives us no spectrum. Without certain types of language, we have nowhere to orient ourselves towards improvement.
“The Road to Character” has got me thinking about individual moral progress.
Edit as of 1/7/19
What I am trying to get at here is the difference between normative and positive statements. Just didn’t have the vocabulary at the time of writing.