This study was conducted in order to lay the base of value education on marital intercourse for married couples in the churches. Reformation churches, which have their theological foundation in Luther’s reformation thought, should be able to teach the value of sexuality and marital intercourse between husband and wife clearly within the churches. It is not only because couples’ marital intercourse performs a very important function for marital satisfaction and stability but also because it has a crucial meaning theologically. Until now, however, reformation churches have neglected education on the value of sexuality in married people. This is not much different from the Medieval Church that, considering sexuality itself a sin under the influence of the thoughts of fathers such as St. Augustine, limited the purpose of couples’ sexual acts to the production of offspring and viewed marital intercourse negatively even until condemning pleasures from having a sexual intercourse. Out of his negative view to sexuality, the Medieval Church forced celibacy on clergymen and this resulted in many side effects.
Luther understood human sexual desire rather as energy and gift from God. Therefore, sexual desire should be used actively through marriage and marital intercourse. Luther believed that human sexual desire itself cannot be a sin but it may be a sin when the energy is used in something other than marital intercourse.
The researcher examined Luther’s thought of marriage and found three major purposes of married couples’ sexual intercourse. First, through sexual intercourse, married couples produce offspring and experience the unity of the bodies so that they may carry out their office as a pastor and teacher to their children. Second, marriage involves vocation and the service of cross. In other words, a husband/wife marries as a vocation to serve his/her spouse, so his/her sexual intercourse should aim at the spouse’s happiness and pleasure. Third, married couples’ sexual intercourse aims at perfect fidelity. This may be connected to the prevention of adultery. Adultery is not limited to physical illicit intercourse but includes the violation of fidelity to each other through sins committed by heart and mouth. Thus, when one’s spouse commits adultery, the sin is attributed not only to the spouse but also to the person who has failed to take care of the spouse. In the conclusion of this study, the researcher presented eight core values of married couples’ sexuality and sexual intercourse that can be adopted as guidelines by the reformation churches.