I don't think He makes that analogy at all. In verse 29 of your passage it says: "29 Then he touched their eyes and said, "According to your faith will it be done to you". Where do believers get their faiths? Do they produce it themselves? No, saving faith comes only from God:
Rom 10:17 : 17 Consequently, faith comes from hearing the message, and the message is heard through the word of Christ.
Now, where do we get ears to hear? :
Prov 20:12 : 12 Ears that hear and eyes that see — the LORD has made them both.
Everything comes from God, not us. If Christ meant that we must cooperate, then the "ears to hear" that the Lord made were incomplete and ineffectual without man's help.
But [FK's teenagers] still have free will and, short of making them robots, that free will can produce catastrophic results no matter how much you 'own' them. They choose to obey you.
Sure they have free will, and do make mistakes. I exercise my "control" over them for their protection to the best of my ability. This ability is incomparable to the control that God has over His children. If I get everything I want, then they will both be spiritually and physically safe during my tenure over them. I have some, but limited power to ensure this. God, OTOH, has limitless power to get what He wants. Therefore, God will use that power to keep His children spiritually safe unto the time of ultimate glory.
Attainment first, award later.
Fair enough. :)
Yes, faith comes from God, but we must answer the call. God does not compel us to answer.