The first four Beatitudes identify felt needs as virtues:  the poor, the mourning, the meek, and the hungry.  The next three identify states of character as virtues.

The first is mercy; the merciful will receive mercy.

Some people think that mercy is not meting out a deserved punishment.  Not so.  Mercy is more akin to gratitude.  “Lord, have mercy,” is better understood as “Lord, continue to be gracious with us.”  That’s why the KJV renders “mercy” as “loving-kindness.”

This has to do with the honor-shame society of the Bible and the satisfaction of personal debts.  Taking the high road with people who owe you something is a virtue that God loves (see Mt 6:15-15; Mk 11:25; Lk 6:35; Eph 4:32).

Jesus told the story of a wealthy landowner who demanded payment of a huge debt from one of his servants (see Mt 18:23-35).  The servant didn’t have it, so the landowner forgave the debt completely.  Later, that same servant demanded payment of a far smaller debt from a fellow servant.  When the second servant couldn’t comply, the first had him thrown into prison.  The landowner then ordered the first service imprisoned.  Jesus said that if we do not forgive the debts of others, then God will not forgive the one we have with him.

Forgiving others, having mercy on the undeserving are all rooted in God’s character.  The real idea of Christianity is to transform us, no to leave us to enjoy the pleasures of this world.  We are adopted as sons of God, and he does so to mold us into the image of his Son.  Therefore, having mercy on others as God has had mercy on us is a sign of that transformation.