In the recent Christian Century there is a theological discussion of same-sex complementarity by Eugene F. Rogers Jr. Here are some of my favourite excerpts:
Consider that in the Middle Ages an abbot could be gendered male, as a physical man; female, as a member of the church; male again, as a priest; female again, as a mother of monks; and female at prayer, as a soul before God. The complementarity theory of male and female turns out to be distinctively modern in confining a person to one gender—and to that extent untraditional. In the Middle Ages, gender could vary according to the greater reality represented.
Granted, medieval gender had features that no one would want to retain. It treated women as defective, and it allowed them to suffer disproportionately from men's sometimes self-serving suggestion that they regard their suffering as Christlike (whereas Christ overturned hierarchy in giving his life for his bride—the opposite of suttee). In the question at issue—does gender confine Christ?—the answer must be no. Christ, as God, is source and consummator of all gender. Christ, as human, assumes humanity, not maleness. Otherwise, he leaves women out of salvation—if "what is not assumed is not redeemed." Or else Jesus needed a woman to complete himself.
To sum up: Ephesians does not require heterosexual complementarity, even if it uses gendered language. A critic has called this interpretation "a refusal to see the obvious." But that's true only if gendered language requires gendered representation. And it doesn't. Otherwise, only women could lead a church gendered as female, and only men could be children of God on the pattern of God's Son. But that's absurd. We do permit men to represent the church, and we do admit women as children of God. An inflexible interpretation of gender confines the reading of scripture, restricts the resources of tradition, ignores the data of creation and reduces salvation to absurdity.
A christological account of gender gives bodies more, not fewer, ways to matter. Because the body of the medieval Christ both retains his circumcision and gains a womb, Christ resembles an intersex person. Because the body of Christ is male in the history of Jesus and female in the history of the church, Christ resembles a transsexual person. Because Christ can be the bridegroom to a male believer, he resembles the same-sex spouse. Gender does not limit Christ, because he is its Lord.