Charles Spurgeon Commentary 1 John 1:5-7

"And this is the message which we have heard from him and announce unto you, that God is light, and in him is no darkness at all. If we say that we have fellowship with him and walk in the darkness, we lie, and do not the truth: but if we walk in the light, as he is in the light, we have fellowship one with another, and the blood of Jesus his Son cleanseth us from all sin." — 1 John 1:5-7 (ASV)

This then is the message which we have heard of him, and declare to you, that God is light, and in him is no darkness at all.

If we say that we have fellowship with him, and walk in darkness, we lie, and do not the truth: 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.

That is, if we walk in the brightest light we can ever know, and if our fellowship with God is the highest that can be enjoyed this side heaven, we shall still need the cleansing blood of Jesus; and, blessed be God, we shall still have it, and we shall still find that it cleanseth us from all sin.