I have been trying to encourage people to use correct ...perghaps the expression is more accurate ...language in regard to the present discussions about who is and who is not allowed to get married.
For me there is a universal human right that all adult human beings should be allowed to enetre into lifelong marital relationship.
More than this, I would maintain that traditional Christian doctrine has a high view of marriage as an agent for social stability and for the secure nurrture of future generations of children
In marriage a new family is established in accordance with God’s purpose, so that children may be born and nurtured in secure and loving care, for their well-being and instruction, and for the good order of society, to the glory of God.
N and N have now come here to be joined in this holy union to which God has led them. They seek his blessing on their life together, that they may fulfil his purpose for them; and they ask us to support them in this prayer. If anyone can show why they may not lawfully be joined in marriage, speak now, or hereafter remain in silence.
(The Australian Anglican Church's current prayerbook)
But I want to dig around that in the next few articles.
At the heart of my thinking is equality, social stability and, primarily, the secure and loving care of children.
This does not seem to me to be intrisnically linked to: the age difference of the parents, the racial or credal difference, the intellectual compatibility (or otherwise) and finally (the cause of the current dicussion in Australia) the requirement for N & N to be of different gender
Here's a couple of links to other interesting articles on this issue