In the gospel of Mathew, Jesus says, “You are the salt of the earth”, and “you are the light of the world”. First of all, its interesting to see that Jesus didn't say here that he(Jesus) is the salt and light, but he is pointing to the disciples and saying that they are the salt of the earth and light of the world.
If a Christian makes a statement that the world is full of darkness, an immediate question can be, you were given the task to be the light. What the hell are you doing?
If a Christian says that the life of the earth is tasteless, then its an attack on us only, as we don’t take the role of being the salt seriously.
Each person’s relationship with salt and light are unique. When some adds much salt, some adds less in the food. There is definitely a huge diversity. Same is true with light too. We need light, but won’t like to be in hot boiling sun too, with a lot of light. So how much light or salt each person requires depends on circumstances; or its a unique feature.
Now what does it mean? Being a light in one person’s life is very different from being light in another person’s life. Being light of the world or salt of the earth should respect the uniqueness of that person. Just as Jesus deals with each person respecting their uniqueness and singularity, if we appreciate these dimensions in our living the Christian life, being salt of the earth and light of the earth may not remain abstract realities, but lived examples.