‘Again, a new commandment I do write to you, which thing is true in him and in you, because the darkness is passing away, and the true light already shines. He who says he is in the light and hates his brother, is in the darkness even until now. He who loves his brother abides in the light, and there is no occasion of stumbling in him. But he who hates his brother is in the darkness, and walks in the darkness, and does not know where he is going, because the darkness has blinded his eyes.'
But he will now also bring them the new commandment. This is revealed in the new commandment given by Jesus (John 13:34) that they love one another as He has loved them. It is something which therefore, unlike the false teaching they are being offered, is true both in Christ and in them, for He loves them, and they are to love one another (John 13:34). And it comes with the recognition that the true Light is already shining (compare Matthew 4:16; John 1:4-5; John 1:9; John 3:19; John 8:12; John 12:46), and the darkness is passing away. Thus all who are true and who recognise that Light will walk in it and will love their brothers, and will not stumble, nor cause others to stumble, and they will be loved by Him. There will be love and unity among those who walk in His light.
In order to grasp the full meaning of these verses we must read them in the light of Jesus' teaching in John's Gospel concerning himself as the Light in contrast with other false light which is only darkness. There He declared Himself to be the light of the world (John 8:12; John 9:5) and warned that any other light was darkness (compare Matthew 6:23). Only those who followed Him would not walk in darkness (John 12:35). And He warned that those who did not believe on Him as the Light and become sons of Light, would, as here, find themselves walking in darkness and not know where they were going (1 John 2:11; John 12:35-36).
So this is John's challenge to those who are seeking to lead the churches astray. It would seem possible that they were referring to a light that they offered, a light that could come to men through their teaching, a light coming in the darkness, a new light, a better light, which men must follow them to receive, possibly a light that they claimed was bringing, a new slant, a new truth, a new teaching, a new ‘knowledge' (gnosis?). It was a light that was little concerned with sin, yes, even denied that it was sin. His reply is that that is not so. There is no new light. The true Light has already come. It is already shining, and the darkness is already on its way out, it is ‘passing away'. Nothing more is needed. No new light is required. Any new light can only lead men astray. All is found in Christ Who is already as a Light among them dispelling the darkness and bringing men into His light. And it is a light that is very much concerned with sin. Thus they must stay with the old truths that they have been taught.
It would also appear that these new teachers had by their teaching brought dissension and disagreement and had aroused hatred in some wayward members of the church who had turned against those who held and proclaimed the old truths, possibly accusing them of keeping this new light from them. Thus he warns that the test of the true light being among them is that they love their brothers who preach Christ truly, who proclaim the light of the world. Not to love them is proof that they have fallen away from the truth.
‘Again, a new commandment I do write to you.' This is a warning that they take heed to themselves lest the light that is in them be darkness, that they beware of being led astray. The new commandment is that they ensure that they show love to those brothers who are responsible for the churches, who preach Christ truly, thus revealing that they are abiding in the light. For to hate those who truly preach Christ is to love darkness.
‘Which thing is true in him and in you, because the darkness is passing away, and the true light already shines.' This new commandment he is writing is true in Christ, and true in His people, because they enjoy shared love, Christ's love for them and their love for one another, and this because darkness is passing away and the true Light is already shining. He is calling on them to recognise and stand by the truth, that the true Light is already among them and there is no place for anything new. Let them look to the One about Whom they learned from the beginning, and Who is at this time working among them, already bringing light and dispelling darkness. If they are ‘in Him' they will do so, for in Him this is true. And if they are true to Him it will be true in them too.
‘The darkness is passing away.' Compare 1 John 2:17 where the world is passing away. Thus the thought is not just that the darkness is going, but that it is transitory and doomed. This darkness is the darkness of sin (1 John 1:5-10), of the power of darkness (1 John 5:19 with Colossians 1:13), of false teaching (1 John 2:11).
‘He who says he is in the light and hates his brother, is in the darkness even until now. He who loves his brother abides in the light, and there is no occasion of stumbling in him. (He leads no one astray). But he who hates his brother is in the darkness, and walks in the darkness, and does not know where he is going, because the darkness has blinded his eyes.' The position of these people is tested by the new commandment which passes its verdict on them. They have come with new light, saying that they are in the light, and yet they do not love the brothers who are faithful to the Gospel and abiding in the Light that is already shining. Thus they are in fact revealing that they are in darkness, as is proved by the fact that they are rejecting the true Light. But those who love the faithful preachers of the Gospel, those who hold to the truth, abide in the Light. They cause none to stumble. They lead none astray.
But those who hate the true brethren prove themselves to be in darkness, and walk in darkness, and do not know where they are going (John 12:35), because their eyes have been blinded by darkness. So he has very much in mind here the words of Jesus in His declaration that He is the light of the world (John 8:12; John 9:5), and His warning that when they no longer have Him as their light men will walk in darkness and not know where they are going (John 12:35). He warns that this is what is happening here. The true Light is being rejected for the false, and many are going into darkness. And it is proved by their hatred, contrary to Jesus' commandment, of those who proclaim the true Light. They do not love the truth.