Blessed are the merciful, for they shall receive mercy. — Matthew 5:7
Forgiveness is only real for him who has discovered the weakness of his friends and the sins of his enemy in his own heart and is willing to call every human being his brother. — Henri Nouwen, Generation Without Fathers
Sometimes we receive mercy in exchange for mercy on an obvious and human level. When we show compassion, when we help others in their troubles and temptations rather than exploiting, condemning or ignoring them, they are more likely to extend compassion to us in our troubles. But the hope of reciprocity isn’t a reliable basis for compassion. Some faithful people will be merciful to us whether or not we are merciful. Some people will not show us compassion however compassionate we strive to be. (Consider what happened to Jesus.)
Some say this Beatitude reflects a theological quid pro quo: Other people may respond unpredictably, but God will forgive us our sins if, and only if, we forgive the sins of other people. There’s a good Scriptural basis for this view. There’s also the Gospel assertion that God sends rain on the just and the unjust, and my experience of God’s mercy shown to me even when I have been lacking in compassion. I don’t know how this works from God’s side.
I do know that when I lack compassion for other people I am less able to receive compassion. I cherish grudges, far too often, against those who have hurt me or others whom I love. I stop paying attention to and seeking to help those people when I feel angry or afraid of further hurt. But sooner or later I always find myself doing something reminiscent of the hurtful action I’ve refused to understand or forgive. My action may be different, but its springs—selfishness, cowardice, resentment, lack of discipline—are the same, and eventually I can’t help knowing that. Then all the bitterness I held toward that other person rebounds on me. The person I offended may forgive me, God may forgive me, but I can’t open myself to their forgiveness until I am also willing to forgive the people who have offended me, and to help them back toward wholeness as I wish to be helped.