“In the third place, from this ordinance of creation God has himself exempted three categories of men, saying in Matthew 19[:12], “There are eunuchs who have been so from birth, and there are eunuchs who have been made eunuchs by men, and there are eunuchs who have made themselves eunuchs for the sake of the kingdom of heaven.” Apart from these three groups, let no man presume to be without a spouse. And whoever does not fall within one of these three categories should not consider anything except the estate of marriage. Otherwise it is simply impossible for you to remain righteous. For the Word of God which created you and said, “Be fruitful and multiply,” abides and rules within you; you can by no means ignore it, or you will be bound to commit heinous sins without end.

Don’t let yourself be fooled on this score, even if you should make ten oaths, vows, covenants, and adamantine or ironclad pledges. For as you cannot solemnly promise that you will not be a man or a woman (and if you should make such a promise it would be foolishness and of no avail since you cannot make yourself something other than what you are), so you cannot promise that you will not produce seed or multiply, unless you belong to one of the three categories mentioned above. And should you make such a promise, it too would be foolishness and of no avail, for to produce seed and to multiply is a matter of God’s ordinance [geschöpffe], not your power.

From this you can now see the extent of the validity of all cloister vows. No vow of any youth or maiden is valid before God, except that of a person in one of the three categories which God alone has himself excepted. Therefore, priests, monks, and nuns are duty-bound to forsake their vows whenever they find that God’s ordinance to produce seed and to multiply is powerful and strong within them. They have no power by any authority, law, command, or vow to hinder this which God has created within them. If they do hinder it, however, you may be sure that they will not remain pure but inevitably besmirch themselves with secret sins or fornication. For they are simply incapable of resisting the word and ordinance of God within them. Matters will take their course as God has ordained” (Luther’s Works, vol. 45, p.18-19).

“In the second place, after God had made man and woman he blessed them and said to them, “Be fruitful and multiply” [Gen. 1:28]. From this passage we may be assured that man and woman should and must come together in order to multiply. Now this [ordinance] is just as inflexible as the first, and no more to be despised and made fun of than the other, since God gives it his blessing and does something over and above the act of creation. Hence, as it is not within my power not to be a man, so it is not my prerogative to be without a woman. Again, as it is not in your power not to be a woman, so it is not your prerogative to be without a man. For it is not a matter of free choice or decision but a natural and necessary thing, that whatever is a man must have a woman and whatever is a woman must have a man.

For this word which God speaks, “Be fruitful and multiply,” is not a command. It is more than a command, namely, a divine ordinance [werck] which it is not our prerogative to hinder or ignore. Rather, it is just as necessary as the fact that I am a man, and more necessary than sleeping and waking, eating and drinking, and emptying the bowels and bladder. It is a nature and disposition just as innate as the organs involved in it. Therefore, just as God does not command anyone to be a man or a woman but creates them the way they have to be, so he does not command them to multiply but creates them so that they have to multiply. And wherever men try to resist this, it remains irresistible nonetheless and goes its way through fornication, adultery, and secret sins, for this is a matter of nature and not of choice” (Luther’s Works, vol. 45, p.18).

“In the first part we shall consider which persons may enter into marriage with one another. In order to proceed aright let us direct our attention to Genesis 1[:27], “So God created man … male and female he created them.” From this passage we may be assured that God divided mankind into two classes, namely, male and female, or a he and a she. This was so pleasing to him that he himself called it a good creation [Gen. 1:31]. Therefore, each one of us must have the kind of body God has created for us. I cannot make myself a woman, nor can you make yourself a man; we do not have that power. But we are exactly as he created us: I a man and you a woman. Moreover, he wills to have his excellent handiwork honored as his divine creation, and not despised. The man is not to despise or scoff at the woman or her body, nor the woman the man. But each should honor the other’s image and body as a divine and good creation that is well-pleasing unto God himself” (Luther’s Works, vol. 45, p.17).

“This third point seems to me to be the most important of all, as well as being the most useful. For without a shadow of doubt it is not only a matter of marital obligation, but can completely eclipse all other sins. False natural love blinds parents so that they have more regard for the bodies of their children than they have for their souls. It was because of this that the sage said, “He who spares the rod hates his son, but he who loves him is diligent to discipline him” [Prov. 13:24]. Again, “Folly is bound up in the heart of a child, but the rod of discipline drives it far from him” [Prov. 22:15]. Or again, “If you beat him with the rod you will save his life from hell” [Prov. 23:14].

Therefore, it is of the greatest importance for every married man to pay closer, more thorough, and continuous attention to the health of his child’s soul than to the body which he has begotten, and to regard his child as nothing else but an eternal treasure God has commanded him to protect, and so prevent the world, the flesh, and the devil from stealing the child away and bringing him to destruction. For at his death and on the day of judgment he will be asked about his child and will have to give a most solemn account. For what do you think is the cause of the horrible wailing and howling of those who will cry, “O blessed are the wombs which have not bore children, and the breasts which have never suckled” [Luke 23:29]? There is not the slightest doubt that it is because they have failed to restore their children to God, from whom they received them to take care of them” (Luther’s Works, vol. 44, p.13).

“In comparison with this one work, that married people should bring up their children properly, there is nothing at all in pilgrimages to Rome, Jerusalem, or Compostella, nothing at all in building churches, endowing masses, or whatever good works could be named. For bringing up their children properly is their shortest road to heaven. In fact, heaven itself could not be made nearer or achieved more easily than by doing this work. It is also their appointed work. Where parents are not conscientious about this, it is as if everything were the wrong way around, like fire that will not bum or water that is not wet.

By the same token, hell is no more easily earned than with respect to one’s own children. You could do no more disastrous work than to spoil the children, let them curse and swear, let them learn profane words and vulgar songs, and just let them do as they please. What is more, some parents use enticements to be more alluring to meet the dictates of the world of fashion, so that they may please only the world, get ahead, and become rich, all the time giving more attention to the care of the body than to the due care of the soul. There is no greater tragedy in Christendom than spoiling children. If we want to help Christendom, we most certainly have to start with the children, as happened in earlier times” (Luther’s Works, vol. 44, p.12-13).

“Third, [the doctors say] that marriage produces offspring, for that is the end and chief purpose of marriage. It is not enough, however, merely for children to be born, and so what they say about marriage excusing sin does not apply in this case. Heathen, too, bear offspring. But unfortunately it seldom happens that we bring up children to serve God, to praise and honor him, and want nothing else of them. People seek only heirs in their children, or pleasure in them; the serving of God finds what place it can. You also see people rush into marriage and become mothers and fathers before they know what the commandments are or can pray

But this at least all married people should know. They can do no better work and do nothing more valuable either for God, for Christendom, for all the world, for themselves, and for their children than to bring up their children well” (Luther’s Works, vol. 44, p.12-13).

“Thus the doctors {of theology} have found three good and useful things about the married estate, by means of which the sin of lust, which flows beneath the surface, is counteracted and ceases to be a cause of damnation.

First, …. It is an outward and spiritual sign of the greatest, holiest, worthiest, and noblest thing that has ever existed or ever will exist: the union of the divine and human natures in Christ….

Second, [the doctors say] that marriage is a covenant of fidelity. The whole basis and essence of marriage is that each gives himself or herself to the other, and they promise to remain faithful to each other and not give themselves to any other. By binding themselves to each other, and surrendering themselves to each other, the way is barred to the body of anyone else, and they content themselves in the marriage bed with their one companion. In this way God sees to it that the flesh is subdued so as not to rage wherever and however it pleases, and, within this plighted troth, permits even more occasion than is necessary for the begetting of children. But, of course, a man has to control himself and not make a filthy sow’s sty of his marriage.…” (Luther’s Works, vol. 44, p.9-12).

My advice is that parents persuade their children not to be ashamed to ask their parents to find a marriage partner for them. Parents should make it clear from the start that they want to advise their children so that they in their turn may remain chaste and persevere in expectation of marriage. In return, children should not become engaged without the knowledge of their parents. You are not ashamed, are you, to ask your parents for a coat or a house? Why be foolish then, and not ask for what is far greater, a partner in marriage? Samson did it. He entered a city and saw a young maiden who pleased him. Thereupon he immediately goes back home and says to his father and mother, “I have seen a young maiden whom I love. Dear parents, get me this girl for a wife” [Judg. 14:1–2]” (Luther’s Works, vol. 44, p.11-12).

“But, secondly, we must have a Savior who is also our Brother, who is of our flesh and blood, who became like us in all respects but sin. And in the children’s Creed {that is, the Apostles’ Creed} we say, sing, and confess: “I believe in Jesus Christ, the only-begotten Son of God the Father Almighty, conceived by the Holy Ghost, not by Joseph, born of Mary, a true, natural man who suffered, was crucified, died, rose from the dead on the third day, ascended into heaven, and sits on the right hand of God, coequal with the Father in power and glory.” With a cheerful heart I may declare: “I believe in Jesus Christ, God’s only Son, who sits on His right hand as my Advocate. He is of my flesh and blood; yes, He is my Brother. For us men and for our salvation He came down from heaven, became incarnate, and died for our sins.” And John, too, introduced his Gospel with the theme of the eternal deity of Christ when he said: “In the beginning was the Word”; “this Word,” he added later, “became flesh.” At the proper time we shall hear more about this” (Luther’s Works, vol. 22, p.24).

“It {Marriage} is an outward and spiritual sign of the greatest, holiest, worthiest, and noblest thing that has ever existed or ever will exist: the union of the divine and human natures in Christ. The holy apostle Paul says that as man and wife united in the estate of matrimony are two in one flesh, so God and man are united in the one person Christ, and so Christ and Christendom are one body. It is indeed a wonderful sacrament*, as Paul says [Eph. 5:32], that the estate of marriage truly signifies such a great reality. Is it not a wonderful thing that God is man and that he gives himself to man and will be his, just as the husband gives himself to his wife and is hers? But if God is ours, then everything is ours.

Consider this matter with the respect it deserves. Because the union of man and woman signifies such a great mystery, the estate of marriage has to have this special significance. This means that the wicked lust of the flesh, which nobody is without, is a conjugal obligation and is not reprehensible when expressed within marriage, but in all other cases outside the bond of marriage, it is mortal sin. In a parallel way the holy manhood of God covers the shame of the wicked lust of the flesh. Therefore, a married man should have regard for such a sacrament*, honor it as sacred, and behave properly in marital obligations, so that those things which originate in the lust of the flesh do not occur [among us] as they do in the world of brute beasts” (Luther’s Works, vol. 44, p.10).

* Written in 1519, Luther uses the word “sacrament” in a wide sense to mean an estate instituted by God, not that marriage gives forgiveness.