1-john 2:8

Which thing is true in him and in you - It is true that Christ loved the world so well as to lay down his life for it; and it was true in them, in all his faithful followers at that time, who were ready to lay down their lives for the testimony of Jesus. There is a saying in Synopsis Sohar, p. 94, n. 51, that may cast some light on this passage: That way in which the just have walked, although it be Old, yet may be said to be New in the love of the righteous. The love that the righteous bear to God and to each other is a renewal of the commandment.

The darkness is past - The total thick darkness of the heathen world, and the comparative darkness of the Mosaic dispensation, are now passing away; and the pure and superior light of Christianity is now diffusing its beams everywhere. He does not say that the darkness was all gone by, but παραγεται, it is passing away; he does not say that the fullness of the light had appeared, but ηδη φαινει, it is now shining and will shine more and more to the perfect day; for the darkness passes away in proportion as the light shines and increases.

Again, a new commandment I write unto you - "And yet, that which I write to you, and particularly enjoin on you, deserves in another sense to be called a new commandment, though it has been also inculcated from the beginning, for it was called new by the Saviour himself." Or the meaning may be, "In addition to the general precepts which I have referred to, I do now call your attention to the new commandment of the Saviour, that which he himself called new." There can be no doubt here that John refers to the commandment to "love one another," (see 1 John 2:9-11), and that it is here called new, not in the sense that John inculcated it as a novel doctrine, but in the sense that the Saviour called it such. For the reasons why it was so called by him, see the notes at John 13:34.

Which thing is true in him - In the Lord Jesus. That is, which commandment or law of love was illustrated in him, or was manifested by him in his contact with his disciples. That which was most prominent in him was this very love which he enjoined on all his followers.

And in you - Among you. That is, you have manifested it in your contact with each other. It is not new in the sense that you have never heard of it, and have never evinced it, but in the sense only that he called it new.

Because the darkness is past, and the true light now shineth - The ancient systems of error, under which people hated each other, have passed away, and you are brought into the light of the true religion. Once you were in darkness, like others; now the light of the pure gospel shines around you, and that requires, as its distinguishing characteristic, love. Religion is often represented as light; and Christ spoke of himself, and was spoken of, as the Light of the world. See the notes at John 1:4-5. Compare John 8:12; John 12:35-36, John 12:46; Isaiah 9:2.

2:8 Again, I do write a new commandment to you - Namely, with regard to loving one another. A commandment which, though it also was given long ago, yet is truly new in him and in you.It was exemplified in him, and is now fulfilled by you, in such a manner as it never was before. For there is no comparison between the state of the Old Testament believers, and that which ye now enjoy: the darkness of that dispensation is passed away; and Christ the true light now shineth in your hearts.