“Jesus says, “You are the salt of the earth; but if the salt has become tasteless, how can it be made salty again?” It is no longer good for anything except to be thrown out and trampled under people’s feet.” Matthew 5:13
Disciples today would do well to remember that they run the risk of uselessness in the Lord’s mission if they relegate themselves to the shelf and not, in appropriate ways, apply themselves in the very contexts in need of their salty presence (that is, salty as defined here in Matthew’s gospel).
The disciple’s presence is required throughout the earth, especially in those areas running the risk of spoiling or in the bland corners in need of life-giving flavor. In fact, it is precisely in the unsavory and/or rotting contexts where salt is most necessary.
Following this salty comment, Jesus introduces another word picture:
“You are the light of the world. A city set on a hill cannot be hidden; nor do people light a lamp and put it under a basket, but on the lampstand, and it gives light to all who are in the house. Your light must shine before people in such a way that they may see your good works, and glorify your Father who is in heaven” (Matthew 5:14-16).
Notice that both here and in the instruction given about salt earlier that the entire world is in view. Jesus tells his disciples they are the “salt of the earth” and here he says that they “are the light of the world” With this big picture in mind Jesus continues by suggesting that the light given off by a city set on a hill is fairly conspicuous to the surrounding areas that are more in the dark. Light from such a city is an especially powerful presence amid darkness, providing illumination, perspective, and, perhaps, guidance to those in the darkness. Disciples have not been given the light of Christ (John 1:4; 8:12) to keep for themselves or to only turn on in the safety of their carefully insulated spheres of influence. Instead, Jesus demands:
“Your light must shine before people in such a way that they may see your good works, and glorify your Father who is in heaven” (Matthew 5:16).
Those who need to see this will not happen upon life and truth-giving light by accident. Light must shine where it can be seen (in the shadows) so that those in the dark might be directed to the Father in heaven and potentially bring him glory. Unfortunately, many are choosing to shine their light only in well-lit and more comfortable areas, neglecting, as Jesus encourages here, to shine what they have been given where it is most needed—in the darkness.
Peter provides a good summary for us: we are ambassadors that need to proclaim His excellencies, His Gospel. Our conduct must be above reproach and we do good deeds so that God is glorified.
“But you are a chosen race, a royal priesthood, a holy nation, a people for His own possession, that you may proclaim the excellencies of Him who called you out of darkness into His marvelous light...
Beloved, I urge you as sojourners and exiles to abstain from the passions of the flesh, which wage war against your soul. Keep your conduct among the Gentiles honorable, so that when they speak against you as evildoers, they may see your good deeds and glorify God on the day of visitation. 1 Peter 2:9-12