Earlier quoted context omitted.
When you say liberal, do you mean liberal but still will not do gay marriages?
It doesn't make sense to call gay partnership a marriage. Marriage is a strictly defined cultural phenomenon meaning a relationship between a man and a woman with the original intention to continue the family by having kids.
You need to review your history on marriage including, but by no means limited to, what the bible has to say on such matters.
The biblical view of marriage is vastly different to simply "a man and a woman wanting to procreate", itself took on and in places redefined millennia of tradition that pre-dated it, and given how much of that definition the church now ignores (allowing divorce, no longer requiring the stoning non-virgins, to cite two of many examples) I don't think ignoring something that isn't actually stated in the text anyway should be a significant problem.