The first half of first John 1:7 states that we should walk in the light just as Jesus walked in the light, and is in the light.
But what does it mean to walk in the light? And what does it mean when Jesus says, "you are the light of the world," in Matthew 5:14?
When considering these questions, we first must define what this light is. There are several possibilities but only one of these stands out above the rest. David proclaims in Psalm 27 that "the Lord is my light and my salvation." Then Jesus says, "I am the light of the world," in John 8:12.
So the answer is, in fact, God.
Knowing this, we can now move on to the bigger questions, such as what it means to walk in this light and what it means to be the light.
The first question is the easier of the two to answer. When we are called to walk in the light, this means that we are called to walk with God. But what does walking with God entail? One could say that this means we are to uphold his commandments and live a life of love after the example of Christ. This is difficult to do, but can be done. However, this is missing an aspect. Living a life like Christ is in itself not a religion, but a lifestyle, and while these two things can affect each other, they should not substitute one another. In other words, religion may affect lifestyle, but lifestyle should not become religion.
So what, then, is the missing aspect?
It is the second question: what it means to be the light.
To illustrate this question, I will use a metaphor. We can agree that God is good, so then it is safe to call the light as good. Since we can define the light as good, we can then define darkness as evil or sin, anything that corrupts the good, for the sake of this example.
Let's say you are walking down the street on a sunny day and you notice your shadow. This shadow is really a bit of darkness that is created when the light shines by your body. You should also notice that while the sun is high, your shadow is small, and when the sun is low, your shadow is large. This then can be applied to us as humans. We all have this area of darkness or sin in our lives that is our shadow. When God is high in our lives this shadow may be smaller, and when God is low in our lives it may be larger.
So how, then, does this relate to our question? We should recall that in Matthew, Jesus didn't call us to just walk in the light, but to be the light. So then does light have a shadow?
The answer is no. If we go back to our example and say that instead of walking down the street during the day, you are now walking down it at night. But this time you are the light. In other words, every part of your being would emit light. As a result, you would have no shadow.
That is really what it means to be the light of the world: to walk with God, not just in the light, but as the light!
We are called to be lights, to go forth in the presence of God, without sin.
