Hate the sin but love the sinner. Most of us with a church affiliation, past or present, have probably heard this expression. For me the statement was an attempt to clarify how the church member could reconcile the need to love and the requirement to judge. It was too obvious that loving and judging a person simultaneously was hard if not impossible. The act of condemning fostered hatred not benevolence, so there needed to be some way to explain how this was supposed to work for the Christian.
More recently I have come to see this statement in a new, more positive light. The new way is to conclude that we are called to exercise judgment in relation to behaviors and not people. In other words, we are to identify sinful behaviors and to shun them but not to label the sinful individual as a bad person because of their sins.
There is ample NT evidence to support this different thinking. All have sinned. To be guilty of one law is to be guilty of all. While we were yet sinners, Christ died for us. These verses and others establish an absolute equality of sinfulness across all of humanity. We are all equally sinful and despite that fact Christ died for everyone, no exceptions. If I insist that someone is a bad person I must include myself in that judgment. Now that's not very appealing.
To conclude that bad behavior does not make me a bad person is mindboggling to consider, much less verbalize. But then Jesus and the NT writers were definitely a mindboggling group.