Adapted from "Beyond 'IDo': What Christians Believe about Marriage," c 2001 Wm. B. EerdmansPublishing Company.

It might surprise you to know that, in the beginning, the church took relatively little interest in marriage. Early in church history, celibacy was the preferred state. It was practically sacred. The Apostle Paul said as much in 1 Corinthians, 7:1. And marriage? Well, it was all but ignored.

As one writer puts it, "When asked, some priests might say a blessing as a favor, just as they'd say a blessing over a child's first haircut." Roman law spelled out the requirements for marriage and most early Christians were content to "render unto Caesar" in matters pertaining to marriage.

Marriage was typically announced rather than pronounced. I'll come back to this distinction later, but for now it's important simply to recognize the difference between announced and pronounced marriages. Early on, families would simply announce there was going to be a marriage, and the church took little notice.

Centuries rolled by with virtually no change to this arrangement. But then something began to happen. Historians don't agree on the details, but what seems clear is that power became an issue. Slowly and unevenly, the church exerted its control over Europe's social and political life, writing laws pertaining to marriage, family, and sex. In 774, the pope gave Charlemagne, the Holy Roman Emperor, a set of writings that defined marriage and condemned all deviations from it.

But it wasn't until 1215 that the Roman Catholic Church formally decreed marriage a sacrament. Equally important, the church established a systematic canon law for marriage--with a system of ecclesiastical courts to enforce it.

These actions profoundly shaped our understanding of marriage. In 1517, when Martin Luther nailed his theses to the church door in Wittenberg, among his concerns were the Catholic Church's rules about marriage. In 1520, Luther publicly burned the canon law. The battle had begun.

The most obvious issue Protestants addressed was marriage as sacrament. Protestants believed that only those acts Jesus told us to perform could be sacraments. And nowhere does Jesus tell his followers to get married. Reformers like Calvin were people of the Word, and the Word--in their view--didn't put marriage in the same category as baptism or the Lord's Supper.

Centuries later, that's still the official Protestant viewpoint. Marriage isn't a sacrament, but it is sacramental. Over the years it has become one of the rites of the church, and so typically has the look and feel of a sacrament. Protestants believe, as one liturgy puts it, that in marriage "husband and wife become one, just as Christ is one with the church." That's an extraordinary statement, and it has a sacramental ring to it, but what does it mean exactly?

Christians believe something is supposed to happen in a marriage relationship that is profoundly mysterious. In the liturgy we refer to marriage as a "mystical union." In Genesis 2:24 the powerful description of this relationship is "one flesh." It is the most profound relationship possible, deeper in many ways than the relationship between parent and child.

Catholic theology has a helpful insight on this point. Marriage as sacrament, their theologians say, refers to the months and years of married life more than it does to the wedding ceremony. In other words, God's grace becomes visible not only at the church as the vows are spoken, but during a lifetime of shared experiences.

For some Christians, especially Protestants, this may be a new insight into sacraments. We think of a sacrament as something that happens at church. It happens during worship, lasts for a few minutes maybe--and then it's over. In reality, though, a sacrament isn't something bound by a liturgy or a rite. Worship may come to end, but a sacrament has an enduring quality.

One more important bit of history. During the Reformation, not only did Protestants reject marriage as a sacrament; they also changed its very definition. And with this change, a social revolution began. Marriage went from being something that was announced to something that was pronounced--from something privately made to something publicly bestowed.

Protestants instituted several requirements that, depending on the region, had to be observed. A marriage had to involve a public ceremony presided over by a priest and attended by witnesses. The couple being married had to obtain parental consent (up to age 21 or even, in some places, 25). And the marriage had to be entered in a public register of marriages.

The Roman Catholic Church, stung by Protestant criticism, eventually went along. In 1563 the Council of Trent decreed that a marriage not publicly performed in front of the parish priest was invalid. But no Protestant group had the civil authority to bestow public recognition on a wedding, and Protestants weren't prepared to wait a thousand years, as the Catholic Church had, in order to build that power. So they handed it off to the local government.