Say that you rail and your rail with your children about all kinds of things: drugs and rock music and Christian music and weak Christianity and sugar and white bread and recycling and ‘those’ people and bad literature and mud on their boots and dirty houses and vaccinations and feeding babies and chocolate and vitamins and natural childbirth, how will your children know which of these things is really important? Maybe one day they find out that some Christians eat sugar and they are nice lovely people who truly love the Lord but from hearing you day in and day out he thought that anyone who ate sugar had a free ticket to hell. Now every single thing you have tried to teach your child ever has been undermined by your passionate intensity.
Be on guard against self-righteousness disguising itself as holiness. Morality, if I dare say it, is a "minor"; the gift of grace through the redemption of Jesus Christ must be the major theme of parenting.