Genesis 4:19

For the laying down of the law of once marrying, the very origin of the human race is our authority; witnessing as it emphatically does what God constituted in the beginning for a type to be examined with care by posterity. For when He had moulded man, and had foreseen that a peer was necessary for him, He borrowed from his ribs one, and fashioned for him one woman; whereas, of course, neither the Artificer nor the material would have been insufficient (for the creation of more). There were more ribs in Adam, and hands that knew no weariness in God; but not more wives in the eye of God. And accordingly the man of God, Adam, and the woman of God, Eve, discharging mutually (the duties of) one marriage, sanctioned for mankind a type by (the considerations of) the authoritative precedent of their origin and the primal will of God. …

Since, then, Adam was the father of both lines, the father, that is to say, both of the line which belonged to the earthly, and of that which belonged to the heavenly city, when Abel was slain, and by his death exhibited a marvellous mystery, there were henceforth two lines proceeding from two fathers, Cain and Seth, and in those sons of theirs, whom it behoved to register, the tokens of these two cities began to appear more distinctly. For Cain begat Enoch, in whose name he built a city, an earthly one, which was not from home in this world, but rested satisfied with its temporal peace and happiness. …

12. The creation of the first man should teach us to reject more marriages than one. There was but one Adam and but one Eve; in fact the woman was fashioned from a rib of Adam. Thus divided they were subsequently joined together in marriage; in the words of scripture “the twain shall be one flesh,” not two or three. “Therefore shall a man leave his father and his mother, and shall cleave unto his wife.” Certainly it is not said “to his wives.” Paul in explaining the passage refers it to Christ and the church; making the first Adam a monogamist in the flesh and the second a monogamist in the spirit. As there is one Eve who is “the mother of all living,” so is there one church which is the parent of all Christians. …

Carnal men abuse virginity, and the pleasure-loving bring forward the following verse in proof, Cursed be every one that raiseth not up seed in Israel . But we, made confident by God the Word that was made flesh of the Virgin, answer that virginity was implanted in man’s nature from above and in the beginning. For man was formed of virgin soil. From Adam alone was Eve created. In Paradise virginity held sway. Indeed, Divine Scripture tells that both Adam and Eve were naked and were not ashamed . But after their transgression they knew that they were naked, and in their shame they sewed aprons for themselves. And when, after the transgression, Adam heard, dust thou art and unto dust shalt thou return , when death entered into the world by reason of the transgression, then Adam knew Eve his wife, and she conceived and bare seed . …

Serenus : You have propounded two not unimportant questions, to which I will reply, to the best of my ability, in the order in which you have raised them. We cannot possibly believe that spiritual existences can have carnal intercourse with women. But if this could ever have literally happened how is it that it does not now also sometimes take place, and that we do not see some in the same way born of women by the agency of demons without intercourse with men? especially when it is clear that they delight in the pollution of lust, which they would certainly prefer to bring about through their own agency rather than through that of men, if they could possibly manage it, as Ecclesiastes declares: “What is it that hath been? The same that is. And what is it that hath been done? The same that is done. …