Unlike love, mercy is not an emotion. One can love another person without ever expressing it openly. But mercy needs to be shown, it involves action. Unlike love which may not always be available from others, mercy can be asked for. Even a convict against whom the final judgement has been pronounced, can make an appeal for mercy to a higher authority.
“God, be merciful to me this sinner!” is the shortest but complete prayer that anyone can possibly pray. (Luke 18:13) It is echoed throughout the Book of Psalms. It is the petition with which many people approached Jesus and he heard them and cured them of their afflictions.
The concept of mercy was explained by Jesus through his parable of the unmerciful or ruthless servant. (Matthew 18:23-35) Briefly, the parable runs somewhat like this: “There was a king whose servant owed him a huge sum of money and he wanted the money back. The servant was not in a position to return it and he asked the king for time. The king was merciful and he wrote off his massive debt. However, this servant later met one of his fellow servants who happened to owe him a small debt. He grabbed his debtor by the throat, would not listen to his plea, and put him in jail. When the king learnt about this, he was greatly annoyed. He called him and said, ‘You wicked man! I forgave you all that debt because you pleaded with me. Should you not have had mercy on your fellow servant, as I had mercy on you?’ The angry king ordered that he may be made to repay his debt using coercive means.”
The lesson from this parable is that it is God’s requirement that we show mercy to others, else we will not be shown mercy by God. However, there is another positive law of reciprocity that is also in operation in God’s kingdom. As Jesus has said, “Blessed are the merciful, for they will receive mercy.” (Matthew 5:7)