I think the biggest error Christians make is in expecting the "Church" to do the entire work of evangelism, ministry, and education; both to the lost and to our children. It's like in school, where we send our children to be taught, but we understand hopefully that we are expected to oversee homework ourselves. Christian Education starts at home. Whether it be Christian Musical History, Bible memorization, Study, Prayer, or Bible reading, nothing will be caught that is not taught. This is not to negate the work of the Holy Spirit in the lives of individuals who are truly taught by their relationship with Christ and develop a Spiritual foundation in God's Word without people to teach them. It does happen. But, do you want to wait and see, when your kids are grown, if they will be one of those few who teach themselves about Christ? I didn't think so.