"You are the salt of the earth; but if salt has lost its taste, how shall its saltness be restored? It is no longer good for anything except to be thrown out and trodden under foot by men.
"You are the light of the world. A city set on a hill cannot be hid. Nor do men light a lamp and put it under a bushel, but on a stand, and it gives light to all in the house. Let your light so shine before men, that they may see your good works and give glory to your Father who is in heaven.
"Think not that I have come to abolish the law and the prophets; I have come not to abolish them but to fulfill them. For truly, I say to you, till heaven and earth pass away, not an iota, not a dot, will pass from the law until all is accomplished. Whoever then relaxes one of the least of these commandments and teaches men so, shall be called least in the kingdom of heaven; but he who does them and teaches them shall be called great in the kingdom of heaven. For I tell you, unless your righteousness exceeds that of the scribes and Pharisees, you will never enter the kingdom of heaven. Matthew 5:13–20 (RSV)
Grace is so simple. It is simple for by it, our sins are forgiven, and we are raised to heaven where Jesus dwells in the unity of the Holy Trinity. We can do nothing to merit grace. It comes to us as a sheer gift. Among the great mysteries of the Father, grace is central to our life in Christ.
We abuse God's grace, treating it like a 'get out of jail free card' and not the life-changing mercy that it is. True, this is nothing new among Christians, Luther, after he surveyed the parishes around Wittenberg, wrote:
Although the people are supposed to be Christian, are baptized, and receive the holy sacrament, they do not know the Lord's Prayer, the Creed, or the Ten Commandments, they live as if they were pigs and irrational beasts, and now that the Gospel has been restored they have mastered the fine art of abusing liberty. Martin Luther - 1528
Jesus is clear that not one small letter of God's Law has been set aside that we may ignore it. We have not been redeemed by Jesus so that we may go our own way. Many want this from our Lord, a pat on the head, 'your sins are forgiven, try to be better,' and off we go. Grace is treated as if all God was interested in was letting our sins pass. It insults Jesus on the Cross to think of God's grace in this way.
We are the salt of the earth; in Christ, we now have a purpose beyond ourselves. As salt is essential for life, so are we essential for living and sharing the life-giving Gospel. If we receive the grace of God solely for ourselves, we have become spoiled salt.
Jesus also calls us the light of the world. A light hidden is useless and leaves people in darkness. We are to let our light shine. When a child is baptized, we light a candle, speaking Jesus' words: Let your light so shine before men, that they may see your good works and give glory to your Father who is in heaven.
Yes, we are free in Christ, so we might use our freedom to worship our Lord and spread His Good News to the ends of the earth.