John Calvin on 1 John 2:6

6 He that saith he abideth in him As he has before set before us God as light for an example, he now calls us also to Christ, that we may imitate him. Yet he does not simply exhort us to imitate Christ; but from the union we have with him, he proves that we ought to be like him. A likeness in life and deeds, he says, will prove that we abide in Christ. But from these words he passes on to the next clause, which he immediately adds respecting love to the brethren.

1 John 2: 7-11

7. Brethren, I write no new commandment unto you, but an old commandment which ye had from the beginning. The old commandment is the word which ye have heard from the beginning.

7. Fratres, non mandatum novum mandment scribo vobis, sed mandatum vetus, quod habuistis ab initio: mandatum vetus est sermo quem audistis ab initio.

8. Again, a new commandment I write unto you, which thing is true in him and in you: because the darkness is past, and the true light now shineth.

8. Rursum mandatum novum scribo vobis, quae est veritas in ipso et in vobis; quia tenebrae transeunt, et lumen verum jam lucet.

9. He that saith he is in the light, and hateth his brother, is in darkness even until now.

9. Quia dicit se in luce esse, et fratrem suum odit, in tenebræ est adhuc.

10. He that loveth his brother abideth in the light, and there is none occasion of stumbling in him.

10. Qui diligit fratrem suum, in luce manet, et offendiculum in eo non est.

11. But he that hateth his brother is in darkness, and walketh in darkness, and knoweth not whither he goeth, because that darkness hath blinded his eyes.

11. Qui vero fratrem suum odit, in tenebris ambulat, nec scit quo vadat, quia tenebrae excaecarunt oculos ejus.