Richard B. Gaffin, By Faith, Not by Sight (Paternoster, 2006), page 78:
Ultimately, in the deepest sense, for Paul “our good works” are not ours, but God’s. They are his work begun and continuing in us, his being “at work in us, both to will and to do what please him” (Phil. 2:13). That is why, without any tension, a faith that rests in God the Savior is a faith that is restless to do his will.
In 1 Corinthians 4:7 Paul puts to the church those searching rhetorical questions, “Who makes you different from anyone else? What do you have that you did not receive? And if you did receive it, why do you boast as though you did not?” (NIV). These questions, we should be sure, have the same answer for sanctification as for justification, for our good works as well as for our faith. Both, faith and good works, are God’s gift, his work in us. The deepest motive for our sanctification, for holy living and good works, is not our psychology, not how I “feel” about God and Jesus. Nor is it even our faith. Rather, that profoundest of motives is the resurrection power of Christ, the new creation we are and have already been made a part of in Christ by his Spirit.