Beloved, I am writing you no new commandment, but an old commandment which you have had from the beginning; the old commandment is the message which you have heard [the doctrine of salvation through Christ]. Yet I am writing you a new commandment, which is true (is realized) in Him and in you, because the darkness ( moral blindness) is clearing away and the true Light ( the revelation of God in Christ) is already shining. Whoever says he is in the Light and [yet] hates his brother [Christian, born-again child of God his Father] is in darkness even until now. read more.
Whoever loves his brother [believer] abides (lives) in the Light, and in It or in him there is no occasion for stumbling or cause for error or sin.