Train up a child in the way he should go, And when he is old he will not depart from it.
Proverbs 22:6 NKJV
Children are faultless and blameless at birth, as they grow, we are their first contacts, hence they learn their first lessons from us.
The Lord has given them to us, it is our duty to train them in the ways of the Lord.
The Lord Almighty will help us to help us to train them.