As Christians we are all aware of Jesus’ words that his followers were to be the “light of the world” (Matthew 5:14), but how do we accomplish that – what exactly is involved in being the light God wants us to be?
Fortunately, the apostle John answers that question for us in his first epistle. John begins his letter, in fact, by stressing that “God is light, and in him is no darkness at all” (1 John 1:10). He continues in the second chapter of his epistle by showing that it is our responsibility to not only reflect that light, but also to live in it – to become part of it – and he shows us how we can know that we are being successful in this:
“Anyone who claims to be in the light but hates a brother or sister is still in the darkness. Anyone who loves their brother and sister lives in the light, and there is nothing in them to make them stumble. But anyone who hates a brother or sister is in the darkness and walks around in the darkness. They do not know where they are going, because the darkness has blinded them” (1 John 2:9-11).
If we look carefully at what John tells us in these verses, we see that he presents three tests, three ways we can know that we are, indeed, “in the light” and able to “be” the light we are called to be. First he gives us the most basic test of love, stressing that if love is manifest throughout our lives we are living in the light (1 John 2:9).
Next, John shows that a person living in love is living in obedience – there is nothing in them to make them stumble (1 John 2:10). This is not to say that we are perfect, of course (1 John 1:8), but that our way of life is one that seeks and follows obedience to God: “If we say we have fellowship with him while we walk in darkness, we lie and do not practice the truth. But if we walk in the light, as he is in the light, we have fellowship with one another, and the blood of Jesus his Son cleanses us from all sin” (1 John 1:6-7). John makes the need for obedience even more explicit in the following chapter: "We know that we have come to know him if we keep his commands. Whoever says, 'I know him,' but does not do what he commands is a liar, and the truth is not in that person” (1 John 2:3-4).
Finally, although it is easier to miss than the first two points John makes regarding our relationship with the light, John speaks of those who do: “… not know where they are going, because the darkness has blinded them” (1 John 2:11). The point here is that those who do not walk in the light are in darkness – meaning they do not see and understand spiritual things as they should. They do not understand the truth. To put the same thought positively, if we are walking in the light, we will have an understanding of spiritual truth. This thought underlies John’s comment later in his letter that: “… whoever lives by the truth comes into the light …” (John 3:21). Living in the light involves understanding and living by the truth.
The apostle Paul made this connection even more directly when he wrote: “The god of this age has blinded the minds of unbelievers, so that they cannot see the light of the gospel…” (2 Corinthians 4:4). In fact, Paul’s writings dovetail with those of John perfectly in this matter. Notice what he tells the Christians at Ephesus: “for the fruit of the light consists in all goodness, righteousness and truth” (Ephesians 5:9). These points are exactly those mentioned by John in only slightly different wording. Combining John’s three aspects of walking in the light with Paul’s summary of the “fruit” or result of living in the light, we see: love=goodness, obedience=righteousness, truth=truth.
These, then, are the three tests and proofs of our walking in the light. If we really are walking in such a way that the light of God may be seen in us, we will be walking in love, obedience, and truth. Other scriptures make it clear that one or the other of these aspects is not enough. We can have truth without love, we can have obedience without love, and we can love at least to some degree without obedience or truth. Both John and Paul show us that we must have all three of these aspects of light in our lives, and that it is not enough to see the light, we must also be the light.