I believe that might have been Jesus Christ, and not an FR poster.
"He that loveth father or mother more than me, is not worthy of me: and he that loveth son or daughter more than me, is not worthy of me."
Now while that's not an explicit command to action in and of itself, the action of casting out the sinner is easily more Scripturally defensible than ignoring the sin.
Those presuming on the love of Christ should read the seven letters to the seven churches that open the book of The Revelation with the understanding that these are epistiles dictated to St. John DIRECTLY from the mouth of Jesus Christ.
Investigating the historical fate of those Churches should prove very illuminating.
Why should we be concerned about the sins of someone who isn't a follower of God? Would Mary Cheney be somehow more Christlike if she was a straight unbeliever than if she was a homosexual one? Isn't worrying about her sexuality like rearranging the deck chairs on the titanic? We should be worried about her soul, not her sinfullness. One doesn't come to Jesus by quitting sin. One quits sin by coming to Jesus.
You must have the ability to understand that homosexuality is no more or less than a sin than greed, etc. Yet, it seems to get alot more attention. Why?
If Cheney's daughter were an ambitious and greedy businesswoman, would we even be having this conversation? If not, why not?
Fine. If you would look at your child, that you have raised and loved since the beginning of their life, through all their tears and laughter and 'cast them out' because they're gay, that would be between you and your conscience. If I had to make that decision, I certainly know what my reaction would be...