82 Having now gone over all the cases in which Faustus finds fault with the Old Testament, and having attended to the merit of each, either defending men of God against the calumnies of carnal heretics, or, where the men were at fault, showing the excellence and the majesty of Scripture, let us again take the cases in the order of Faustus' accusations, and see the meaning of the actions recorded, what they typify, and what they foretell. This we have already done in the case of Abraham, Isaac, and Jacob, of whom God said that He was their God, as if the God of universal nature were the God of none besides them; not honoring them with an unmeaning title, but because He, who could alone have a full and perfect knowledge, knew the sincere and remarkable charity of these men; and because these three patriarchs united formed a notable type of the future people of God, in not only having free children by free women, as by Sarah, and Rebecca, and Leah, and Rachel, but also bond children, as of this same Rebecca was born Esau, to whom it was said, "You shall serve your brother;" and in having by bond women not only bond children, as by Hagar, but also free children, as by Bilhah and Zilphah. Thus also in the people of God, those spiritually free not only have children born into the enjoyment of liberty, like those to whom it is said, "Be followers of me, as I also am of Christ," but they have also children born into guilty bondage, as Simon was born of Philip. Again, from carnal bondmen are born not only children of guilty bondage, who imitate them, but also children of happy liberty, to whom it is said, "What they say, do; but do not after their works." Whoever rightly observes the fulfillment of this type in the people of God, keeps the unity of the Spirit in the bond of peace, by continuing to the end in union with some, and in patient endurance of others. Of Lot, also, we have already spoken, and have shown what the Scripture mentions as praiseworthy in him, and what as blameworthy and the meaning of the whole narrative.
Source: Reply to Faustus the Manichaean (New Advent)