Here's what he said yesterday in the House of Lords:
Speaking in Monday's debate, the archbishop said the government's plans would fundamentally alter understanding about the purpose of marriage."The new marriage of the Bill is an awkward shape with same gender and different gender categories scrunched into it, neither fitting well," he said.
"The concept of marriage as a normative place for procreation is lost, the idea of marriage as covenant is diminished, the family in its normal sense. The result is confusion. Marriage is abolished, redefined and recreated."
He added: "For these and many other reasons, those of us in the Church and other faith groups who are extremely hesitant about the Bill in many cases hold that view because we think traditional marriage is a cornerstone of society.
"Rather than adding a new and valued institution alongside it for same gender relationships, which I would personally strongly support to strengthen us all, this Bill weakens what exists and replaces it with a less good option that is neither equal nor effective."
Welby, like so many men in the church, confuses love with sex. the purpose of Marriage is not about 'procreation'. When I see my wife, my first thought is not how to produce more children with her. Like most couples, making love is mostly about avoiding 'procreation' and simply expressing deep affection for one another. I married for love,and not just sex. Older couples who are not able to have children are not an affront to the 'purpose of marriage'.
Marriage, is however still the best place to raise children. That is precisely why Gay couples should be allowed to marry, as they are already legally and rightfully able to raise children. Marriage for same sex couples strengthens society, the family, and the helps children raised by same sex couples live in equality with other children.
But what is this notion of family 'in it's normal sense'? For Jesus, he spent most of his ministry with folk outside of this 'normal sense' of family. He even attacked the traditional notion of family on several occasions.
Jesus was more interested in love and equality than notions of normality and patriarchy - and it is about time the Church leaders paid attention to his wider sense of justice and inclusivity.