"But abuse does not destroy the proper use."
NT Wright tossed this little phrase into paragraph about political power, but it implies a definition of good and evil that bears exploring and repeating.
Sin is not a thing. Evil is not a thing.
Good is a thing (or rather many things). Pleasure, beauty, purpose, power, existence! These are good, in and of themselves. Some of the typical targets of Christian vilification, sex, alcohol, dancing, gambling, tobacco, etc. are not evil, nor is engaging them inherently sinful.
They are not evil, because evil is not a thing!
Evil is the perversion of good, not its opposite. Therefore adultery is the sin, not sexual pleasure; drunkenness is the sin, not alcohol; addiction not smoking; titillation not dancing; you get the picture. Something is evil when it takes some good thing and misuses it; a public official using his political clout to oppress the poor; a woman using her beauty to diminish other women; enjoying the pleasure of food with no regard to issues of larger importance; separating sexual intimacy from personal intimacy; again, you get the picture.
Sin, truly, is "missing the mark."
...and so, we must realize that engaging in perverse behavior is no greater an evil than abstaining (or encouraging others to abstain) from behavior that is healthy!
Of course, there are appropriate times to set aside pleasurable and otherwise good activities (1 Corinthians 8:13), but there is the equal danger of allowing prudish people to set the agenda in a way that denies the inherent goodness of God's creation (Colossians 2:16-23).
Jesus is the Lord of Life, who has come to share that abundant life with us, and we must learn to embrace His creative goodness. We can no longer be the prudish people who cannot talk about sex without getting red cheeks and hot collars, instead, we must begin to recognize (and to teach the world) that it is not the porn star who is sexual, but the monogamous husband and wife. We are the possessors of the reality, of which the world has only parody.
Our witness is hampered by drunkenness, surely; but we must begin to acknowledge that our witness is just as tarnished by an inability to enjoy fine wine.