Being shown a beautiful garden, a visitor went on about the beauty of God's handiwork. Finally, the gardener replied, "You should have seen it when God did it by Himself!" God didn't create a finished product. Even the Garden of Eden was made to require Adam's assistance. God could have made all of us fully mature from the beginning, but that isn't how He did it. He made us all as helpless babies, requiring parents to nurture and teach us for a fairly long time. And God takes a chance on our trying to do it ourselves, and not doing it right.
Once when I was trying to research a Father's Day lesson, I found many stories of fathers. The surprising thing is that most of them were not very good at the job. We find favoritism and neglect over and over. We find God's people being told to teach their children well, and we find that generations grow up not having learned. We also see God over and over again intervening in their history, and bringing them back to Him. The encouraging thing is that even though we are all imperfect, God uses flawed people.
One of the outstanding servants of God was David, often referred to as "a man after God's own heart." David, however, for the most part, was not a good father. We read of his son Amnon sons raping his sister, and David not dealing with him. We find Absalom killing Amnon in revenge, and fomenting rebellion against his father, and when Absalom is in turn killed, David inordinately mourns him but seemingly not mourning his victims. In David's old age, we see Adonijah trying to seize power, even though David had named Solomon as heir to the throne. We do see David giving good advice to Solomon, and Solomon leaving us the wisdom of Proverbs, but even Solomon, with great wisdom from God, still failed miserably with his own son Rehoboam.
What has been passed down to us in God's word is not a glittering record of unbroken successes, but a record of failure and redemption. None of us are perfect parents, but we can see that God's Kingdom is made up of repentant and forgiven people. This is our lesson: we cannot be perfect on our own, but we can repent and be forgiven, picked up, dusted off, and used of Him.