St. Gregory the Dialogist ca. 540-604
The good we do is both of God and of ourselves. It is God’s through prevenient grace, ours through obedient free will. For if it is not God’s, why do we give thanks to Him in eternity? And again, if it is not ours, why do we hope that a reward will be given us? It is not improper that we give thanks; for we know that we were anticipated by God’s gift. And again, it is not improper that we seek a reward, because we know that by obedient free will we chose to do what is good. (Morals on the Teaching of Job 33.21.40)