“Do not judge, or you too will be judged. For in the same way you judge others, you will be judged, and with the measure you use, it will be measured to you.
Too often I hear people who are talking about others behind their backs, or just plain rude to others, even though they know nothing about them. For instance, I heard someone saying how much they disliked a co-worker because the co-worker just wasn't very approachable. Afterwards, I told them "well, you know their father just died a couple of weeks ago, I doubt they've gotten over that quite yet." They instantly looked guilty.
I'm not saying we should always worry that we are going to say something wrong about someone, I'm saying that we just should be cautious with our words and actions.