Until recently, I had never heard of someone described as "THAT neighbor" before. I had no idea what the phrase meant. I have since figured it out.
Ironically, the one who first introduced me to the term has turned out to be the purest embodiment of the word's definition that I have ever encountered. Now knowing the definition, I can say that over the course of my lifetime, I have had several "THAT neighbors": growing up, the pot smoker next door; the drug dealer upstairs; the video game-playing insomniac raver; and now... well, I'd rather not give a description yet.
Here's my working, evolving definition of "THAT neighbor":
Someone who lives next door to you (or above or below you) who habitually, carelessly breaks the spoken or unspoken rules of your neighborhood.
A shorter definition might be much simpler:
"THAT neighbor" = the neighbor that nobody ever wants
"THAT neighbor" = a bad neighbor
So here's the real issue at hand: now that we have identified who these people are and what they do, we have to decide how we're going to deal with, and interact with, them.
The bottom line is this: I'm convinced that God demands of us all that we treat all others with infinite respect, as we would wish to be treated - even when we screw up - because all people are inherently valuable to him. But more than that, I believe that I am personally expected to act with an impossible amount of grace and patience - to demonstrate a level of love that I am incapable of showing to anyone in my own strength.
With great difficulty, I say here: "I love my neighbor." Now comes the hard part: showing it. By how I act, what I say - both to her and to others about her, and how often I go out of my way to show her that I care.