There is nothing we can offer to God more precious than good will. But what is good will? To have good will is to experience concern for someone else’s adversities as if they were our own, to give thanks for our neighbor’s prosperity as for our own; to believe that another person’s loss is our own, and also that another’s gain is ours; to love a friend in God, and bear with an enemy out of love, to do to no one what we do not want to suffer ourselves, and to refuse to no one what we rightly want for ourselves; to choose to help a neighbor who is in need not only to the whole extent of our ability, but even beyond our means. What offering is richer, what offering is more substantial than this one? What we are offering to God on the altar of our hearts is the sacrifice of ourselves.
St Gregory the Great