Corrupt Words

Ephesians 4:29 says, "Let no corrupt word proceed out of your mouth, but what is good for nessecary edification, that it may impart grace to the hearers."
Out of all the things we Christians do wrong, this has to be pretty high up on the scale. Not only in the form of cursing, which is becoming more rampant, but in the sense of sarcasm and bringing others down. As Christians, we are suppose to be in the world, but not of it, meaning that we are to live in the world but not conform to its call or adapt to the "normality" of it. We are to be lights shinning on a hill, but how can lights shine when they are exactly like the darkness they try to reach out to?
The first and formost form of corrupt word that I think is cursing. When we throw down the "F-bomb", what it really says is either, "I have anger issues" or "I am conforming to the world." People will curse because it is cool. Honestly that is just the reason people do it. In a group of friends, people will start conversing and as soon as someone lays down the first blow, the others soon follow. But really, how can we blame them? We constantly watch movies in which cursing isn't really that bad, and we hang out with friends who don't follow Christ and we hear them say dirty and corrupt words. Sure, one looking for sin can always find it, but do we really try to guard the hearts of our young ones to teach them edifying things?
If I asked you if it was possible for everything you say to come across as what is good for necessary edification, how would you answer?
I often struggle with the line between joking and lying, and I have come to the conclusion that not many know where that line is either. However, I think we can really lose focus on what our goal is by staring at this line in between such things. If you ever wanted to know the secret behind the tightrope walker, he'll tell you that he focuses on the end, and not the rope itself. When I learned to rollerblade, my father told me to look ahead, and not at the floor because where you look, there you will go. The same is true with this imaginary line. If you really try to find the balance, you will fall every time, but if you focus on pursuing Christ, then you will be more successful.
Notice how Paul, the writer of Ephesians, says that edification is necessary. Do we really think this is true? Do we consider edification necessary?  Do we impart grace to those who hear? And most importantly, are we chasing after God? - Forsake All