Therefore, my dearly beloved, as we have now proved by our former testimonies from Holy Scripture that there is in man a free determination of will for living rightly and acting rightly; so now let us see what are the divine testimonies concerning the grace of God, without which we are not able to do any good thing. And first of all, I will say something about the very profession which you make in your brotherhood. Now your society, in which you are leading lives of continence, could not hold together unless you despised conjugal pleasure. Well, the Lord was one day conversing on this very topic, when His disciples remarked to Him, “If such be the case of a man with his wife, it is not good to marry.” He then answered them, “All men cannot receive this saying, save they to whom it is given.” And was it not to Timothy’s free will that the apostle appealed, when he exhorted him in these words: “Keep thyself continent”? He also explained the power of the will in this matter when He said, “Having no necessity, but possessing power over his own will, to keep his virgin.” And yet “all men do not receive this saying, except those to whom the power is given.” Now they to whom this is not given either are unwilling or do not fulfil what they will; whereas they to whom it is given so will as to accomplish what they will. In order, therefore, that this saying, which is not received by all men, may yet be received by some, there are both the gift of God and free will.
Reproduced in full. Translation: Nicene and Post-Nicene Fathers, series 1, vol. 5 (Schaff, 1887), public domain (Public domain).