Yes, you must show mercy to others. If you do not show mercy, then God will not show mercy to you when he judges you. But the one who shows mercy can stand without fear before the Judge.
“Then the king will say to the evil people on his left, ‘Get away from me. God has already decided that you will be punished. Go into the fire that burns forever—the fire that was prepared for the devil and his angels.
Suppose someone is suing you, and you are both going to court. Try hard to settle it on the way. If you don’t settle it, you may have to go before the judge. And the judge will hand you over to the officer, who will throw you into jail.