Justin Taylor gives a sermon illustration that is providentially also in my chapter on the power of a parent’s example. Here is a (very) rough draft of the beginning of that chapter:

Anyone who has ever flown in an airplane can tell you the routine. You are instructed on how to put on a seat belt (Can you slow down? I didn’t quite get that!), how to exit the plane, how to use the seat as a floatation device, and how to put on an oxygen mask in the case of cabin decompression. But in that instruction on the oxygen mask, the flight attendant provides some instruction that is counterintuitive. “Parents flying with young children,” we are told, “Put on your mask first and then put on your child’s mask.” What a strange instruction! Does not that seem backwards? Should not we parents sacrifice ourselves for our children? The answer in this case is, “No.” Why? We are actually more help to our children when we are receiving oxygen fully. It is actually more loving to put our mask on first.

The Power of Example
Your children are watching you. They are watching the people at your church. They are learning about God from you. And as they get older, they are deciding if they want to follow your God. Albert Schweitzer said it this way with only a slight overstatement, “There are only three ways to teach a child. The first is by example, the second is by example, and the third is by example.” Similarly, God’s command to parents to pass on their faith is not directed first to our relationship with our children. It has to do with our relationship to him. In Deuteronomy 6, verses 5 and 6 are directed at the walk of the parents.

Love the Lord your God with all your heart and with all your soul and with all your strength. These commandment that I give you today are to be upon your hearts.

Before God brings us to the teaching of our children in verse 7 and 8, he reminds us of the need we have to love God and to have his word on our hearts. We cannot pass on something we do not have.