God is light and there is no darkness in Him, that is why all of us who walk in His Ways must walk in light because everyone who does not walk in light, has not known God because everyone who is under the will of God is because of himself know the light of our mighty God.
People who walk in darkness can easily fall into a hole due to lack of light. By walking in darkness, it is easier for the enemy to make it easier for you to wage war and not let you know the light of God.
The light of the Lord is what illuminates us so that we can see everything clearer, it illuminates our path, to make us see that only in the hands of God all things are clearer.
5 This then is the message which we have heard of him, and declare unto you, that God is light, and in him is no darkness at all.
6 If we say that we have fellowship with him, and walk in darkness, we lie, and do not the truth:
7 But if we walk in the light, as he is in the light, we have fellowship one with another, and the blood of Jesus Christ his Son cleanseth us from all sin.
1 John 1:5-7 (KJV)
The writer of this letter speaks clearly to us about the light of Jesus, that light that helps us every day, to know His Word and illuminate our path.
That is why, as the author says, if we say that we have fellowship with Him, and walk in darkness, then we lie and we are not practicing the truth of our Lord Jesus. Now, if we walk in the light and speak the truth of Christ, we are in the light, because this is what our God wants from His children, because the blood of our Lord cleanses us from all sin.