Do good to those who hate you; bless those who curse you; and pray for those who mistreat you so that you may be children of the Most High. “But I say this to you who are listening…” thus continues Jesus’ address to the crowd after a series of jibes that appears to have been meant for “those others” ( the curses, vv. 24-26). Turning his attention back to those with him, Jesus proceeded to let them know what was expected of them: “I know you have seen a lot, that you have endured a lot, and that naturally you would feel the need to  do to them as they have always done to you. However, that would be the wrong way to go since such is not your lot. Do not fall into that trap. You have to show them that you hold no grudge against them, and that you truly are children of God your Father. Prove to them that they were acting in ignorance when they mistreated you, that they didn’t know what they were doing. Unlike them, I want you to be merciful just as God your Father is merciful. God’s mercy knows no bounds.”
The mercy of God in which Jesus was asking the crowd to participate is seen in God not  doing because God expects something in return (cf. if you love those who love you…if you lend expecting to be given back…) but rather in the  being of God. God extends God’s mercy to one and all because that is who God is. It is the nature of God to be merciful. Likewise, those to be considered the children of God (literally  fromGod) had to do as God does. Those who wants to be known as having come from God must BE as God IS. God’s action toward God’s creatures must become the new measuring stick for those who wish to be followers of Jesus.