I once heard that Tony Campolo made this statement:  "Love the sinner, hate your own sin." 

I love the way he puts it.  The other adage (love the sinner, hate the sin) has obvious pitfalls, i.e. being judgmental.  I find that we humans are not nearly as good at hating sin in ourselves as we are hating sin we see in other people or "the world".  We may have the best of intentions, but when it comes right down to it, we’re big ole’ log-eyes, swinging our poles around while trying to perform lasic surgery on our friends and neighbors. 

The Hof (my new nickname for Dietrich Bonhoeffer) talked about these same ideas (much more eloquently) in his book The Cost of Discipleship.  Check it out (and hey, watch where you’re swinging that tree!  You could decapitate someone):

Judging others makes us blind, whereas love is illuminating.  By judging others we blind ourselves to our own evil and to the grace which others are just as entitled to as we are.  But in the love of Christ we know all about every conceivable sin and guilt; for we know how Jesus suffered, and how all men have been forgiven at the foot of the cross.  Christian love sees the fellow-man under the cross and therefore sees with clarity.  If when we judged others, our real motive was to destroy evil, we would look for evil where it is certain to be found, and that is in our own hearts.  But if we are on the look-out for evil in others, our real motive is obviously to justify ourselves, for we are seeking to escape punishment for our own sins by passing judgment on others, and we are assuming by implication that the Word of God applies to ourselves in one way, and to others in another.  All this is highly dangerous and misleading.  We are trying to claim for ourselves a privilege which we deny to others.  But Christ’s disciples have no rights of their own or standards of right and wrong which they could enforce with other people; they have received nothing but Christ’s fellowship. Therefore the disciple is not to sit in judgment over his fellow-man because he would wrongly usurp the jurisdiction.

Dietrich Bonhoeffer
The Cost of Discipleship