Considering the modern confusion about sex and marriage, manifested by recreational hooking-up, cohabitation, adultery, no-fault divorce, serial polygamy, and same-sex marriage, the Catholic Church’s unchanging teaching on marriage is probably one of the most comforting treasures I have found.  

“Is marriage from God, or is it a human institution?” If you had asked me this when I was an evangelical Protestant, I would have answered with a series of quotations from Scripture. I believed that God created humans as male and female (Gen. 1:27); with the specific intention that they should complement each other physically and psychologically (“It is not good for the man to be alone. I will make a helper suited to him” Gen. 2:18); that marriage was designed by God (“That is why a man leaves his father and mother, and clings to his wife, and the two of them become one body” Gen. 2:24); that God commanded them, “Be fertile and multiply; fill the earth” (Gen. 1:28). I also believed that the marriage relationship was to last until one of the spouses dies.  Finally, I would point out that every society, recognizing the value of marriage for the good of the spouses and children and the whole social order, guards it with civil laws.  

After I became Catholic, I began to appreciate the way the Church, in her wisdom, ties all these truths together in a deeper and more comprehensive moral vision. In particular, I learned that God designed marriage with two purposes in mind. A shorthand way of naming these two purposes is: bonding and babies. God’s plan for marriage includes both the bond of love between a man and a woman and the procreation and upbringing of children flowing from that love. The idea that revolutionized my understanding of these truths about marriage is that when these two purposes are separated, we lose a substantial part of the good which God intended marriage to bring the spouses, their children, and the whole of society.

Then I learned how the Church helps us fulfill these two purposes of marriage.  Embedded in the marriage vows are four promises which the spouses are asked to make, while relying on the God’s grace to overcome all obstacles and persevere in keeping the promises.  At the wedding, the bride and groom promise each other that they will commit themselves to the marriage freely, faithfully, fully, and fruitfully.

As I explain each of these promises in detail, I hope you will imagine the heaven on earth that marriage becomes when these promises are fully realized, as well as the hell on earth that marriage becomes when these promises are broken.

The first two promises relate to the first purpose of marriage: bonding. The couple binds themselves to each other freely and faithfully.

1)  Freely — Each person must come to the marriage freely, without any external pressure or coercion of any kind and without any deceit.  Perhaps a gal gets pregnant to force her boyfriend to marry her. Or perhaps she tells him she is pregnant to deceive him into marriage.  Freely includes “informed consent,” which means that the prospective spouses are honestly presenting themselves to one other.  I know of a situation where the bride informed her fiancé on the eve of their wedding that she had $10,000 in credit card debt. Surprise!  He still had time to reconsider and get out of the marriage, although not without humiliation.  But imagine what would happen to their marital trust if that information had come out after the wedding?  If a spouse holds back vital information, can God’s plan for unity be achieved?  If trust is broken down from the get-go, will there ever be real unity?

2)  Faithfully — The traditional wedding vows read:  “Forsaking all others…until death do us part.” The spouses promise to be sexually faithful to each other.  There is no double standard here.  All husbands and wives are called to practice marital chastity.  I know of a marriage that ended when the wife discovered that her husband had another woman in his life during their entire marriage.  It doesn’t take much imagination to understand the pain caused when this promise is broken.  Many men are addicted to pornography and, for this reason, may not be able to keep their promise.

The last two promises, fully and fruitfully, relate to the second purpose of marriage:  babies. 

3)  Fully - Each person comes to the marriage fully, bringing his or her entire self to the act which consummates the marriage.  If you have ever wondered why the Catholic Church forbids the use of contraceptives, here is the explanation. Each time a couple engages in marital intercourse, they are physically renewing their marriage vows. (That was certainly a new concept for me!)  But if artificial birth control is used, it is like saying in your wedding vows, “I do, but not all of me and not all the time.”  Contraception, sold to our society with the promise that it would strengthen marriages, has actually made them weaker.  Why?  Artificial birth control drives a wedge between the unitive and the procreative purpose of marriage: it impairs bonding while thwarting the natural fruitfulness of marital intercourse.    (No! no! no! you say.  How can we live without contraception?  What can Catholics do if they simply cannot have a child at a particular time in their lives? The Church, as usual, has a great answer! It is called Natural Family Planning.  I will talk about that treasure in another article). 

4)  Fruitfully — Lastly, the couple promises to come to the marriage fruitfully.  This means that they are open to God’s blessing of new life. If a couple expresses an intention of having no children, and of using artificial birth control to achieve this goal, they cannot be married in the Catholic Church.  Remember what I said revolutionized my understanding of marriage? The two purposes of marriage, bonding and babies—the unitive and the procreative, ought not to be separated.  If the two purposes are separated, and if the four promises are not fully realized, it is not a God-designed marriage.

Does this mean that if a couple is infertile, they cannot have a God-designed marriage?  No.  It does not.  As long as the act of marriage (sexual intercourse) can be completed, and the couple is open to life, their infertility does not negate their marriage.  The important point is that sterility cannot be brought about by their choice and action (whether temporarily, e.g. the pill or condoms, or permanently, e.g. tubal ligation or vasectomy).  

Please continue to follow this line of reasoning, for it also explains why the Catholic Church cannot recognize or bless same-sex marriage.  Even if both men or both women are perfectly healthy and fertile, the two of them cannot biologically complete the act of marriage and, whatever they do sexually, they cannot bring a new life into the world.  The Church does not have the authority to separate the two purposes of marriage, which God joined together in the act of marital intercourse.  As Jesus said in regard to the husband and wife becoming one flesh, what God has joined together, let no man separate.

At this time in history, our society (by the use of contraceptives and by the growing acceptance of same-sex marriage) has chosen to separate bonding and babies and reduce marriage to an emotional bond: “marry the one you love” and “for as long as the love endures.”  While these “marriages” may be given legal recognition, they are far from God’s plan and design.  Although people may think their marriage decisions are their own private affair, ultimately, whenever we go against God’s design, we can expect hurt, chaos, and loss to everyone in our society—especially to our children.  I could give you endless examples, and I know you could too.

The two purposes of marriage, and the four promises which assure their fulfillment, have become my  secure guide and measuring stick as I wade through the political, social and religious issues that are swirling around in our culture today.  I am so thankful for this new Catholic treasure.


Read this next: The Treasure of the Communion of Saints

Melanie Frei was an evangelical Protestant missionary to Hong Kong with her husband Tom, pastor and seminary professor. But when they studied Scripture and Church history, the two of them decided to leave their ministry and enter the Roman Catholic Church. Melanie is the mother of three incredible young adults and three awesome grandchildren and is also a substitute teacher in the Tomah Area School District. Her favorite ministries are leading Bible studies, music and pro-life work. For fun, Melanie is a total fan of BBC dramas and Regency romance.