Augustine of Hippo, On Grace and Free Will Chapter 1: The Occasion and Argument of This Work

With reference to those persons who so preach and defend man’s free will, as boldly to deny, and endeavour to do away with, the grace of God which calls us to Him, and delivers us from our evil deserts, and by which we obtain the good deserts which lead to everlasting life: we have already said a good deal in discussion, and committed it to writing, so far as the Lord has vouchsafed to enable us. But since there are some persons who so defend God’s grace as to deny man’s free will, or who suppose that free will is denied when grace is defended, I have determined to write somewhat on this point to your Love, my brother Valentinus, and the rest of you, who are serving God together under the impulse of a mutual love. For it has been told me concerning you, brethren, by some members of your brotherhood who have visited us, and are the bearers of this communication of ours to you, that there are dissensions among you on this subject. This, then, being the case, dearly beloved, that you be not disturbed by the obscurity of this question, I counsel you first to thank God for such things as you understand; but as for all which is beyond the reach of your mind, pray for understanding from the Lord, observing, at the same time peace and love among yourselves; and until He Himself lead you to perceive what at present is beyond your comprehension, walk firmly on the ground of which you are sure. This is the advice of the Apostle Paul, who, after saying that he was not yet perfect, a little later adds, “Let us, therefore, as many as are perfect, be thus minded,”—meaning perfect to a certain extent, but not having attained to a perfection sufficient for us; and then immediately adds, “And if, in any thing, ye be otherwise minded, God shall reveal even this unto you. Nevertheless, whereunto we have already attained, let us walk by the same rule.” For by walking in what we have attained, we shall be able to advance to what we have not yet attained,—God revealing it to us if in anything we are otherwise minded,—provided we do not give up what He has already revealed.