God's Word commands it.
Proverbs 22:15
Foolishness is bound in the Heart of a Child ; but the Rod of correction shall drive it far from him.
Children belong to God .
God loans Children to Parents .
Parents should Obey God .
Proverbs 22:6
Train up a Child in the Way he should go: and when he is old, he will not depart from it.
Anyone who does not is really a bad parent.
Proverbs 13:24
He that spareth his Rod hateth his Son : but he that loveth him chasteneth him betimes.
There is no "time out" in Hell .