I recognize it as God-orgained. But it is not required to recognize that in order to recognize that man-woman unions are special.
In the same way the heavens declare the glory of God, nature declares the uniqueness and specialness of heterosexuality through the children it produces. God wrote it into our genetic code and it can be seen whether we acknowledge Him or not.
Of course I agree.
I was pointing out that children are not the ONLY reason the state has an interest in marriage.