If I, as a father, use a "carrot" and "stick" approach with my children, when I suppose I am training them for godliness, I believe the results would be sorry, in the main.
Sanctification can be expressed in terms of the fruit of the Spirit, but obedience will never define sanctification. The "good" brother of the Prodigal Son "never disobeyed" the Father's command (Lk.15:29); and yet it took his brother's return to rip the mask off his hatred for his Father.
The beginning of the Spirit's fruitful work is love (Gal.5:22). Here, in the Spirit's work upon the heart, is the
power that was lacking in the stone-writ law. It is the love that produces obedience to the reinscribed law now found in the new heart, not over and outside of the old one.
Simple obedience to command will never produce genuine love, anywhere. It won't produce it in the one obeying, and it won't produce it in the once being obeyed. I don't love my children
because they obey me, nor do I want them to obey me principally for a reward they expect.
However, it seems to me the essence of the "carrot and stick" approach makes sanctification into a new legalism, by measuring it according to the quantity and quality of obedience, complete with rewards and punishments, and tit-for-tat.
My love for my children leads me to give them what they need, including corporal punishment when deserved, when it will do them good. I would not characterize this as the "stick" approach. And I don't think that the "carrot and stick" idea does much justice to the notion of the wise Father's love, or the Spirit's modus operandi for heart-transformation and renewal.
