Grace, a mark of God's Kingdom among us, tends to look backwards to worldly standards. It tends to do the reverse of what seems natural. Jesus showed this when he came to earth as baby, surprising the people who were waiting for a forceful king to rescue them.
Just like Christ, Christians are called to love enemies, feeding them if they're hungry, giving them a drink if they're thirsty. Canceling debts, forgiving people who don't deserve it, praying for those that give them trouble are all part of the Christian life. This is the reversal of grace.