Natural Family Planning International

The answer is that when they married, they freely entered into a covenant of God’s making. They solemnly promised before God and their fellow man that they would exercise caring love for each other from that time until death separates them. They gave themselves, each to the other, totally, without reservation. This is what makes marriage so wonderful. Each person knows his or her own sins and imperfections; each knows that the other has his or her sins and imperfections. Yet they give themselves, each to the other, in caring love, totally and without reservation, for better and for worse, for life. They become “two in one flesh.” This is why the language of the Church generally refers to marital sexual intercourse as “the marriage act.”

Marriage is the key

The Catholic faith teaches that sex is a gift from God even though that gift is frequently misused. Any reading of the Bible or even secular literature quickly shows how frequently and in how many ways men and women have misused the gift of their sexuality.

There is no direct biblical statement that sex is intended by the author of creation to be a renewal of the marriage covenant. However, we can arrive at that core statement by deduction. As will be shown in Chapter 17, “Biblical Foundations,” Sacred Scripture condemns adultery, fornication, homosexual behavior, contraception, masturbation, and bestiality. Thus the only form of sexual intercourse not condemned by Sacred Scripture is non-contraceptive intercourse between a man and woman who are married to each other. I will use the term “honest sex” or “honest sexual intercourse” to designate the sex act taught by Scripture and Tradition to be good: mutually voluntary, non-contraceptive intercourse by a validly married couple.

That leads to an obvious question: what is there about marriage that makes morally good the same physical act that is morally evil outside of marriage? Or to put it the other way, if honest sexual intercourse is (or can be) a moral good within marriage, why is it evil for those who are not married to each other? Certainly God knows that the degree of emotional love felt by unmarried persons is sometimes much stronger than that felt by many married couples. Let’s sharpen the focus a bit more. If Jim and Jane love each other, why is it the grave matter of mortal sin for them to have sexual intercourse on the day before they marry but morally good for them to celebrate their marriage with honest sexual intercourse after they have married?

John F. Kippley
Sex and the Marriage Covenant

The core statement
The core statement of the covenant theology of sexuality is simplicity itself:  “Sexual intercourse is intended by God to be at least implicitly a renewal of the marriage covenant.”

It can be embellished slightly by rephrasing the last part of the statement:  “Sexual intercourse is intended by God to be at least implicitly a renewal of the faith and love and unreserved gift of self pledged by the couple when they entered the covenant of marriage.”

It can be rephrased further in secular terms: “Sexual intercourse is meant to be a renewal of the couple’s own marriage covenant, a symbol of their commitment of marital love.”

Or, in its most secular form: “Sexual intercourse is meant to symbolize the self-giving commitment of marriage.”

Secular phrasing is helpful for conveying the idea to students in schools where religion is not taught and/or where it cannot be taught that sexual intercourse is truly a marriage act and is honest and finds its meaning only within marriage. As an aside, I want to respond to the easily imagined challenge that this concept could not be taught in an American public school because it might be seen as reflecting a religious belief. The response is threefold.  1) Most just laws reflect the natural moral law that has been codified in the Ten Commandments, so there is no difference in teaching that man is not meant to steal from others and teaching that man is not meant to have sex outside of marriage.  2) The ordinary language of cultures all over the world—both in time and in place—supports the notion that sexual intercourse is meant to be a marital act. Any culture that has a taboo on adultery or that sees pre-marital sex by engaged couples as less good than marital sex supports the notion that sex is meant to symbolize the commitment of marriage.  3) Such basic non-sectarian norms of human behavior simply must be taught at every level and place of education, or alleged education is simply not human education, and that, of course, is the problem with much education today.

John F. Kippley
Sex and the Marriage Covenant