1 John 2:3-11

New Revised Standard Version, Anglicised Catholic Edition

³ Now by this we may be sure that we know him, if we obey his commandments. ⁴ Whoever says, ‘I have come to know him’, but does not obey his commandments, is a liar, and in such a person the truth does not exist; ⁵ but whoever obeys his word, truly in this person the love of God has reached perfection. By this we may be sure that we are in him: ⁶ whoever says, ‘I abide in him’, ought to walk just as he walked.

A New Commandment

⁷ Beloved, I am writing you no new commandment, but an old commandment that you have had from the beginning; the old commandment is the word that you have heard. ⁸ Yet I am writing you a new commandment that is true in him and in you, because^[a] the darkness is passing away and the true light is already shining. ⁹ Whoever says, ‘I am in the light’, while hating a brother or sister,^[b] is still in the darkness. ¹⁰ Whoever loves a brother or sister^[c] lives in the light, and in such a person^[d] there is no cause for stumbling. ¹¹ But whoever hates another believer^[e] is in the darkness, walks in the darkness, and does not know the way to go, because the darkness has brought on blindness.