Yesterday I preached one of the most difficult sermons of my short tenure as a minister at my congregation here, giving an all-too brief exposition of Ephesians 5:22-33. This is probably the most important passage on marriage in the New Testament epistles. It ended up being a passionate exhortation to both men and women to dramatize the Gospel through their marital relationship: the model for husband and wife is Christ and his Church, and when this drama is passionately reenacted in marriage in some sense the mysteries become one.
The mystery of marriage is found in the "dance" between husband and wife, a dance which reflects the deeper dance between Christ and his Church, a dance which restores and completes the older dance between the Triune God and his Creation, a dance which in turn manifests the deepest and eternal dance between the Father, the Son, and the Holy Spirit.
That eternal dance, the mutual outpouring, indwelling, and inter-penetration of the Three Persons of the Trinity is given a fancy name by theologians: perichoresis. At its most basic level perichoresis is a dance. The Father gives everything that he is to the Son by breathing out his Spirit to him, and the Son gracefully responds in obedience and love, giving himself completely back to him, by breathing out the same Spirit back to him.
It is in this sense that St. Paul says that God (the Father) is the "head" of Christ (the Son), just as Christ is the "head" of the Christian husband, just as the husband is the "head" of his wife. There is no inequality of being or of substance or of value between the Father and the Son (this is implied by the Son being homoousios with his Father), and yet it is the difference in their activities, actions, works, in other words, in their roles, that allowed for there to be Creation in the first place and which set the stage for Redemption's multifaceted execution. It is because the Father sent the Son (and did not go himself) and because the Son submitted himself wholly to his Father's will, that is, because of the difference in what they have done, that we receive forgiveness of sins, adoption as sons, new life in the Spirit, integration into a people, and hope of resurrection on the last day.
We should not be surprised then to find that the image of God reflected in humanity should require equality of being yet complimentary difference in roles and activities. When God says "Let us make man in our image, after our likeness," he creates humanity "male and female," perfect equality without sameness, created to be perfect compliments. In marriage, the masculinity of the husband reflects the initiating and creating character of God, and the femininity of the wife reflects the nurturing and consummating character of God, particularly as he has manifested this character in the Church and given it to the Church.
Indeed, as the Spirit indwells the Church makes her his holy habitation, the Church is brought up into the perichoresis, into the dance-life of the Holy Trinity in a way that anxiously anticipates the final union and consummation of Creation when the Lord Jesus comes again. Jesus asks his Father, "that the love with which you have loved me may be in them, and I in them," "I in them and you in me, that they may become perfectly one," and for that purpose, "the glory that you have given me I have given to them." Jesus prays that the same relationships of outpouring and indwelling be granted to the Church even though the Church is not (nor will ever be) God in the strict sense of the term. But just as when a husband and wife become united together in matrimony they become one flesh, mystically bound together in spiritual and physical union, without being merged together into the same person, so Christ took on our flesh and bone so that his Church might become flesh of his flesh and bone of his bone. The Church and all believers together have "in-law" become members of that family we call the Trinity. It is what theologians call theosis, glorification, or even deification.
This is what human marriage, with all of its difficulties, frustrations, fights, and disappointments, represents and communicates to us. In marriage God has instituted and ordained a community to reflect his image, his drama of salvation, and the final union that awaits us at the Marriage Supper of the Lamb, and like any symbol properly understood, even a common, sinful, human marriage finds its power by participating in this reality to come. Marriage is a mystery and, for the Christian, a window into the glorification that awaits us. It encourages us in our dance lessons and focuses our attention, not only on the steps, but on the bridegroom who has mastered them all and who is calling us to follow him.