A statement from the French reformer as I continue to comb history's best thinkers on what motivates Christians to obey. Interesting - both Calvin and Turretin (below) draw on Augustine.
"God’s grace, as this word is understood in discussing regeneration, is the rule of the Spirit to direct and regulate man’s will. The Spirit cannot regulate without correcting, without reforming, without renewing. For this reason we say that the beginning of our regeneration is to wipe out what is ours. Likewise, he cannot carry out these functions without moving, acting, impelling, bearing, keeping. Hence we are right in saying that all the actions that arise from grace are wholly his. Meanwhile, we do not deny that what Augustine teaches is very true: ‘Grace does not destroy the will but rather restores it.’ The two ideas are in substantial agreement: the will of man is said to be restored when, with its corruption and depravity corrected, it is directed to the true rule of righteousness. At the same time a new will is said to be created in man, because the natural will has become so vitiated and corrupted that he considers it necessary to put a new nature within."