Salt is good; but if salt has lost its saltiness, how can you season it? (Mark 9:50 NRSV)
What happens to our faith when it is not used? It is of no more value than salt that has lost its taste and gone bad. In Jesus' day salt was not pure salt like we have today, but was harvested with other natural substances that could and did go bad. When that happened, the salt was useless. There was no way to restore the lost taste.
"But if salt has lost its taste," Jesus said, "how can its saltiness be restored?" The only thing to do with such salt is to throw it away. It is no longer valuable; it is worthless. "It is no longer good for anything, but is thrown out and trampled under foot," Jesus said. Faith that has gone by the wayside is useless. You are the salt of the earth, so put your faith to work everyday!
God of faith, keep my eyes and faith focused on serving you. In Jesus' name, Amen.