I notice one thing with people {I would say mostly the unsaved, but I've seen this with Christians too} is that they're "moody", and sometimes for almost no reason, they'll "snap at you, or "show their true colors, and give a selfish or arrogant reply if you say or ask something, Like, they just blurt out what they want, not caring about the other person at all. Even amongst "friends" I've seen this. {Family members too.}. And yes, Christians do this too. Like these people are making you a scapegoat for their own miserable feelings. They give in to their emotions, and just "have at you." {Only thinking of themselves.} Now, the origin of this kind of attitude? I think this "harsh tongue" is part of the fallen nature. Think so?
