A while ago I heard a man ministering to a couple. He encouraged them that their children were "developing a testimony." I've thought of this many times and realize how true it is.
Most parents that I know are doing their best to train their children and teach them what they feel is important. If we could, we would have them make the best and wisest decisions all the time. We would have taught them so well that they wouldn't make mistakes or find themselves in difficult situations.
If it was even possible to parent without making mistakes, (and it's NOT) I think we would have children who know a lot about God, but don't really KNOW Him. They would be like hot-house plants who wouldn't know how to live outside their own homes.
Not only have I made mistakes, but my children have made some of their own. (I know it's hard to believe.) I have 47 years of learning under my belt, and my children can learn from my experiences. But it's not the same as having some of their own. I learned forgiveness from situations where it was essential. I found grace when I reached the end of my own strength. I fell in love with the Lord only when all other loves failed me. It will be the same with my children.
So, what's a parent to do? Teach them everything you know. Then stand by and encourage them when they need it.