There is an irreducible biological or gender component to being a man or a woman.One does not get to choose one’s biology, one’s XY chromosomes. The creation story in Gen. 1-2 makes perfectly clear that the only ‘suitable companion’ for the man was a woman, and this is because God created us male and female in his image. Only so could we perpetuate the human race. Only so could we be mini-creators of more human beings, so mirroring one aspect of God the Creator.At the end of the day either we realize that gender matters, and gender difference is essential to a real Christian marriage, or we totally change the definition of what counts as marriage, what counts as husband and wife, what counts as mother and father Biblically speaking.
I agree with Ben on the merits. However, that's a problematic argument coming from a Wesleyan Arminian. Since "one doesn't get to choose one's biology, one's chromosomes," isn't it unfair, according to stock Arminian ethics, to discriminate against LGBT people?