Train up a child....
"These words which I command you today shall be in your heart. You shall teach them diligently to your children, and shall talk of them when you sit in your house, when you walk by the way, when you lie down, and when you rise up."
Deuteronomy 6:6-7
In other words, all communications in all waking hours would point to God's truths and ways. No attitudes, discussions or suggestion would bring confusing or contrary messages until their minds and understanding have been grounded in truth. This will establish your children in a firm Biblical world view before they face the pressures to conform to world's ways and values.
It is also the essence of Proverbs 22:6
"Train up a child in the way he should go, and when he is old he will not depart from it."