But he who hates his brother is in the darkness, and walks in the darkness, and doesn't know where he is going, because the darkness has blinded his eyes.

 Second, as to its contents, John has been warning his people of the perils of the dark and the necessity of walking in the light and now he says that in every case their best defence is to remember what they are and what has been done for them. No matter who they are, their sins have been forgiven; no matter who they are, they know him who is from the beginning; no matter who they are, they have the strength which can face and overcome the Evil One. When Nehemiah was urged to seek a cowardly safety, his answer was: "Should such a man as I flee?" ( Nehemiah 6:11). And when the Christian is tempted, his answer may well be: "Should such a man as I stoop to this folly or stain my hands with this evil?" The man who is forgiven, who knows God and who is aware that he can draw on a strength beyond his own, has a great defence against temptation in simply remembering these things. 