The teaching of Jesus about turning the other cheek, giving to everyone who begs from you, lending while expecting nothing in return - all this can seem idealistic and quite unrealistic for the rough and tumble world in which we live. Jesus is here sketching the 'ethics of the kingdom': where God's love reigns, people will find themselves living in these ways. But, as long as we are living in a fallen and struggling world, many feel that such a way of living remains an ideal beyond human ability. And it is. In ourselves we find the 'first Adam' and the 'last Adam', the old man and the new man, and the struggle between them is never fully resolved in this life.
But when we love, we find ourselves able to live in the way Jesus asks. Where we like people, are fond of them and want to remain in friendship with them, we find ourselves turning the other cheek, giving whenever we are asked, and lending without expecting anything in return. It is only where we 'fall out of love', or lower our sights from the goal of loving, that we begin to count the cost, measure what we give in terms of what others are prepared to give, and then begin to judge and condemn others.
We must look above and beyond the particular situations and relationships in which we find ourselves, to God and His way of loving. God is our third point of reference, above ourselves, above others. From God we experience forgiveness for ourselves and learn how to be merciful to others. This comes about not just through some kind of external learning but because, as Paul puts it in the first reading, 'the peace of Christ controls our hearts'. As long as our hearts are unhappy we will experience the world as divided and in conflict. We will generate division and conflict to confirm the way our unhappy hearts believe things to be. But the Word of Christ dwelling in us generates gratitude and mercy, the peace that the world cannot give and the love that is to be put on over everything else. Then the teaching of Jesus about turning the other cheek, giving to everyone who asks, lending without expecting anything in return: such behaviour is no longer strange but perfectly normal in the kingdom established by Christ.