The problem is Christianity was being introduced to children as a law, being taught from the Old Testament, as something they had (must) to believe in, simply because their parents are / were Christian. They didn't have a choice. Scripture simply says you should train up a child the way he or she should go, the choice will be clear to them as you teach them.

True Christianity is not "religion" because religion points you towards perfecting yourself, Christianity is not something to work for, not a set of Laws to follow, its evidence of God's Love, its a gift of God.