(Proverbs 22:6 KJV) Train up a child in the way he should go: and when he is old, he will not depart from it.
One of the important requirements to raising Godly children is to be Godly ourselves. You would think that is obvious but consider all the people who send their children to Sunday School or even attend regularly without any real commitment. I remember when we were trying to force our child into a car seat and later to put on the seat belt. This was in the period that cars were required to have them but we were not required to use them. It soon became obvious to us that if we did not do it ourselves, they would never go along with the restriction.
Parents who do not live what they teach are like cars with unused seat belts. Were we serious? Then we needed to buckle up. Are you serious? Then you need to find the seat belts in your life and put them to use.
So? It is never too late to start although it may be late to have the effect obedience could have had.