1 John 2:7-9

Beloved, I am not writing a new commandment to you, but an old commandment which you have had from the beginning; the old commandment is the message which you have heard [before from us]. [John 13:34, 35] On the other hand, I am writing a new commandment to you, which is true and realized in Christ and in you, because the darkness [of moral blindness] is clearing away and the true Light [the revelation of God in Christ] is already shining. The one who says he is in the Light [in consistent fellowship with Christ] and yet habitually hates (works against) his brother [in Christ] is in the darkness until now.