We are to be merciful because God is merciful. We are to give mercy because we have received mercy. We are to be kind, even to ungrateful and evil persons, because that is exactly what God does. “Blessed are the merciful, for they will receive mercy” (Mt 5:7). There are consequences for not showing mercy. “For judgment will be merciless to one who has shown no mercy; mercy triumphs over judgment” James 2:13 (NASB). Being merciful is grateful worship of the Father for His vast mercy to us.
“But love your enemies, and do good, and lend, expecting nothing in return; and your reward will be great, and you will be sons of the Most High; for He Himself is kind to ungrateful and evil men. Be merciful, just as your Father is merciful.” Luke 6:35-36 (NASB)