The Hebrew word for mercy is
CHEN from which comes the meaning of grace, which is an undeserved favor. Graciousness has something to do with one being higher and another being lower. Caesars picked up on this idea and showed "divine" power by being merciful. Obviously they borrowed it from Judaism and Rabbi Hillel in particular.
CHANAN means grace, which is often translated into English as mercy. Many say that only the supreme and sovereign-over-all God can be gracious. Yet Jesus taught us to be gracious or merciful so that we might obtain mercy and thereby become perfect as our heavenly Father is perfect.
In order for CHANAN to function the gracious person lets the undeserved favor to slip out of his hand making it fall into the lap of the lower one; that person is then called CHANOON the gracious one.
There was a slave who borrowed money from his master and when the time to repay the debt came he begged the master for mercy for he could not pay it back. The master said, "You are in luck because I happen to be merciful and since you have mentioned mercy, from my merciful heart I forgive your debt."
The slave was elated and out of the blue came up with a scheme of his own. He thought to himself, 'the softy schmuck just forgave my entire debt, this is an opportunity for me to get ahead so let's see... who owes me money?' He found his first debtor and asked him to repay what he owed, but the poor man was unable to, begging him for mercy. But he responded in an unlikely manner for the law was on his side and he could have easily extract the money by means of legal duress and that's what he did. The debtor was thrown into prison until he should pay back what was owed. When his fellow slaves saw what had happened, they were deeply grieved and came and reported to their lord all that had happened. Then summoning him, his lord said to him, "You wicked slave, I forgave you all that debt because you pleaded with me. Should you not also have had mercy on your fellow slave, in the same way that I had mercy on you?" Then his lord, this time moved with anger rather than mercy, handed him over to the torturers until he should repay all that was owed him.
Jesus concluded the story by saying "My heavenly Father will also do the same to you, if each of you does not forgive his brother from your heart."
Just believing in God's mercy alone without some form of practice is useless for we shall be judged by our works and not by our imaginations or sentiments.
The first coming of Christ deals with mercy and grace for He came to save what's been lost.
At the Nazareth Synagogue Jesus opened the Book of Isaiah (Isaiah 61:1-2) and red the passage, "To set free those who are oppressed, to proclaim the favorable year of the Lord." And then He closed the book. He stopped at the next sentence, "And the day of vengeance of our God."—Judgment.
The Mercy Gate at first was a place of grace and miracles. Then came Jesus's triumphal entry on the Palm Sunday. Also at that same gate God performed miracles through the apostles. But the final entry will by the Messiah the great judge.
We believe that when Jesus returns, according to Scripture, the Beautiful Eastern Gate will be opened; (at present it is closed) and at that time He will enter it as a judge.