The saddest thing for me as a reader was how, in books on the Bible and sex, Vines and Wilson concentrated almost wholly on the biblical negatives, the prohibitions against homosexual practice, instead of giving sustained attention to the high, (yes) glorious Scriptural vision of sexuality. Both authors rightly say that the Bible calls for mutual loving relationships in marriage, but it points to far more than that.
In Genesis 1 you see pairs of different but complementary things made to work together: heaven and earth, sea and land, even God and humanity. It is part of the brilliance of God’s creation that diverse, unlike things are made to unite and create dynamic wholes which generate more and more life and beauty through their relationships. As N.T. Wright points out, the creation and uniting of male and female at the end of Genesis 2 is the climax of all this.
That means that male and female have unique, non-interchangeable glories ”” they each see and do things that the other cannot. Sex was created by God to be a way to mingle these strengths and glories within a life-long covenant of marriage. Marriage is the most intense (though not the only) place where this reunion of male and female takes place in human life. Male and female reshape, learn from, and work together.
Therefore, in one of the great ironies of late modern times, when we celebrate diversity in so many other cultural sectors, we have truncated the ultimate unity-in-diversity: inter-gendered marriage.