Here it is written: “God will judge the immoral and adulterous.” It is not written that God will judge and condemn the married, but rather the whoremongers and adulterers. For if God were to condemn and judge the married people, he would have to condemn himself. But God does not do this, but rather is well pleased with married people, as those who live and walk in his ordinance and creation….
Therefore, those who are married should be cheerful and confident and grateful to God that they are in an estate which has been ordained and blessed by God, of sure hope and assurance that God will keep his ordinance and blessing, regardless of whether it annoys the devil, the pope in Rome, and therefore prompts them to condemn this estate….
I say this for the comfort of all those who are in the married state, that they may be emboldened and encouraged. If all of you who are married are not rich, as not all of you can be rich, then be satisfied with what you have, and let it be your strong consolation that you have been married in accord with divine ordinance, and be assured that God will keep watch over this his ordinance and blessing. Nor do we desire to prevent or force anybody in this matter. (“Sermon at Marriage of Sigismund von Luindenau, 1545” Luther’s Works, v. 51, p.361-362)