Christ said, "You are the salt of the earth." This substance is of great use. It is used for seasoning, preserving food and meat, fertilizing the soil, and for other purposes. People cannot live without salts, and Christ considers his followers so important that without them the world becomes flavorless, and senseless, and repentance ends. Did a small particle of salt ever enter into an open wound in your body, or into your eye? It burns and causes much pain. In this manner, your testimony of the truth and your calling people to turn to God must hit them, make them disturbed, and urge them to be converted.
If you neglect Christ’s command to deny yourself, you will become worthless, and cheaper than the dung, which is applied to the soil. Christ sends out those worthless people that they may be caught as prey by the power of the devil.
Did you hear the call of God? Are you still prepared to deny the blood relationship, and enter into the holy war? Testify of the truth of the gospel without limitation. But if you were not completely prepared to devote yourself to Christ, you should rather not begin to follow him, for our Lord vomits the lukewarm out of his mouth.