And you were dead in the trespasses and sins in which you once walked, following the course of this world, following the prince of the power of the air, the spirit that is now at work in the sons of disobedience—among whom we all once lived in the passions of our flesh, carrying out the desires of the body and the mind, and were by nature children of wrath, like the rest of mankind. (Ephesians 2:1-3 ESV)
The corrupt seed that will grow and blossom into bad fruit is already there when a baby is born, waiting for the right conditions to sprout. No one has to teach a toddler to misbehave, or, as E. K. Simpson wrote in his commentary on Ephesians, “every mother’s son learns to be naughty without book.”1 Grabbing toys, throwing tantrums, pulling one’s cousin out of Grandma’s little rocking chair is natural—and has been since the fall.
These verses apply to all of us, even little children. We enter the world spiritually dead. What follows "dead in trespasses and sins" is a description of this condition as it works itself out in our lives. Remember the story of the children of Hamelin who were led away by the magic sound of the Pied Piper's flute? Someone spiritually dead is a little like that. They are marching along to the music of evil inner powers. They go willingly, but at the same time, the attraction is so strong they cannot turn away.
The real solution to the problem our children and grandchildren are born with, then, is not our discipline. They are powerless to change what they are by nature and we can't we change them, either. Enforcing boundaries may keep them from dancing after the piper, but it won't stop them from loving his music. Rules can help civilize children; rules can teach them what they ought to do. But rules can't make them good.
True hope for the children we love comes from God's gracious nature-changing inner work. (See this explained in the verses that follow—Ephesians 2:4-10). Since any heart change comes through the gospel, which is "the power of God for salvation" (Romans 1:16), our children need to hear the good news over and over. It is possible to have too many rules, but there's no such thing as too much gospel.
There's no such thing as too much prayer, either. If our best parenting cannot change a heart but God's work can, we should be on our knees daily, expressing our helplessness and begging for God's mercy to us and to them.
This all seems obvious to me now, so obvious that I wondered if it was worth a post. But I wish I'd understood this better when my own kids were young, and I thank God I know it in time for my grandchildren.
1E. K. Simpson, The New International Commentary on the New Testament: The Epistles to the Ephesians, page 49.