Conservatives and Christians don't expect people to be morally perfect. In fact, they expect people to be imperfect. But it's about setting goals and bars and realizing that no matter where you set the bar, people will fall short of it. So if you set your bar high, people will fall short but plenty of people will hit that standard or at least get close to it. If you set your bar low, then that's what people will do and plenty will fall short of even that. So if you have low standards, you'll have a bad society and if you have high standards, you'll have a better society.
That's where hiding flaws comes in. By hiding the flaws of parents and heroes behind a wall of secrecy, you don't undermine high standards. By giving the impression that everyone is crooked or promiscuous or messed up, then it undermines any standards to be better than that, regardless of the fact that, sure, you'll never prevent people entirely from being promiscuous or cooked or messed up. And that's the problem with liberals. They believe that people can be perfect if they simply have all the fact. Thus they really think that if you give kids birth control and tell them not to feel bad about having sex that they'll all do the responsible thing and there will be no regrets and no unwanted pregnancies. It just doesn't work that way.
That's where hiding flaws comes in. By hiding the flaws of parents and heroes behind a wall of secrecy, you don't undermine high standards
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I agree. Parents must be role models for their children. Much harm has been done by those who would be their children's friends, rather than their parents. Children usually reject attempts by their parents to offer life's mistakes as a way of teaching lessons. It generally encourages a lack of respect, which is quite the opposite of what a thoughtful parent intends.
Too many parents indulge themselves by offering too much information about their own lives to their impressionable children. It is no wonder that so many young ones have grown so cynical of late.