1Jn 1:5 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.
This then is the message that John has heard. He brings it all together in the statement that God is light and in Him is no darkness at all. What then is the message? John says in the opening verses that he has seen the Christ with his own eyes. With his own ears he has heard God speak to him through the flesh. His eyes beheld Him and he even touched him. He handled the Word of Life. He embraced Him and he hugged Him and he kissed him on the cheek. For over three years he walked with Him, he walked with God and the message that he is now sharing is that in Him there was no darkness at all, they had walked in the light, and in this all-seeing all-knowing light it was impossible to walk in darkness. You simply could not walk with Jesus, could not fellowship with God if you were walking in darkness for God would call you on it.
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. (1Jn 1:7)
What does it mean to walk in the light? It is not a small point, it is a vital point for it has major ramifications for who we are and how we live before men. You will notice that it says that if we walk in this light then we shall have fellowship one with another. Now, perhaps you did not know but there is two possible interpretations of this phrase ” one with another.” Many have believed that it means fellowship with other believers would not be possible if one were walking in the darkness. The other interpretation and the one that I believe and prefer is that “one with another” means having fellowship with God. Now, this will ultimately lead to a breaking in fellowship with other believers who may be walking in the dark, but primarily this scripture speaks to our relationship with God.
A Call To The Remnant 