The gospel scripture for this Sunday, like that of last Sunday, (the "beatitudes") is taken from the Sermon on the Mount in the Gospel According to Matthew - chapters 5-7. These three chapters are a basic catechism for Christian life. They are also very challenging because we are asked to love our enemies and do good to those who hate us! They give us the prayer we say thousands of times - the "Our Father" or "Lord's Prayer" - which challenges us to forgive as God forgives.
Today's challenge is to be "salt of the earth" and "light of the world!" This seems to aim at both interior and exterior integrity. Faith cannot be simply an interior relationship with God. Faith must find expression in love of neighbor as well. I have mentioned in the past a poster I once had that said: "If you were arrested for being a Christian, would there be enough evidence to convict you?" Salt means that faith must permeate everything we do. "Light" will be the result of that interior/exterior integrity. Christianity is more than a humanism which can be manifested in generous behavior. Christianity proclaims God's love manifested in Jesus Christ! This is how we become the salt and light of the world. AMEN