In today's Gospel, Jesus tells his disciples (and us) that we are the salt, and light of the earth.
I usually focus on the "light" part of that statement, mainly because it is more vivid in my mind. However, given that I live in the snow-ridden, northeastern United States, today the salt angle is leaping off the page at me.
Most of us probably know the general interpretation of this passage. Back in Jesus' day, good salt was used to preserve food, much like Christ charged His disciples with preserving His word and the Faith. However, salt that loses its flavor is worthless, and gets tossed out and trampled on - much like sinners could be tossed out of the Kingdom.
(Two notes of interest: One, salt does not lose flavor easily, so this could also be interpreted as "impure, or inferior" salt. Two, if salt gets trampled into farmland, it can ruin entire crops - much like sinners can ruin otherwise Holy people.)
But this winter's weather has led me to another analogy. Every other day, it seems like we face more snow and ice here in my part of the world. When the road crews put high quality street salt down, we all walk confidently and remain upright (read: remain good disciples of Christ). When they use inferior salt, or the salt has become trampled into the ground from too much traffic, our road instantly becomes very slippery - causing people to fall (read: sin).
So whether we are preserving the Faith, or helping people walk steady on their path to Paradise, I think our mission is pretty clear!