One who humiliates another person in public ... even though he may be a scholar and may have done many good deeds, nevertheless loses his portion in the eternal world (Ethics of the Fathers 3:15).
Imagine a situation: you have a fine home, a well-paying job, a comfortable car, and a substantial retirement annuity. If you do a single thoughtless act, you will lose everything you have worked to achieve: home, job, car, and savings. What kind of precautions would you take to avoid even the remotest possibility of incurring such a disaster? Without doubt, you would develop an elaborate system of defenses to assure that this event would never occur.
The Talmud tells us that everything we have worked for during our entire lives can be forfeited in one brief moment of inconsideration: we embarrass another person in public. Perhaps we may say something insulting or make a demeaning gesture. Regardless of how it occurs, the Talmud states that if we cause another person to turn pale because of being humiliated in public, we have committed the equivalent of bloodshed.
Still, we allow our tongues to wag so easily. If we give serious thought to the words of the Talmud, we would exercise the utmost caution in public and be extremely sensitive to other people's feelings, lest an unkind word or degrading gesture deprive us of all our spiritual merits.