“And by this we know that we have come to know him, if we keep his commandments. Whoever says “I know him” but does not keep his commandments is a liar, and the truth is not in him, but whoever keeps his word, in him truly the love of God is perfected. By this we may know that we are in him: whoever says he abides in him ought to walk in the same way in which he walked. Beloved, I am writing you no new commandment, but an old commandment that you had from the beginning. The old commandment is the word that you have heard. At the same time, it is a new commandment that I am writing to you, which is true in him and in you, because the darkness is passing away and the true light is already shining. Whoever says he is in the light and hates his brother is still in darkness. Whoever loves his brother abides in the light, and in him there is no cause for stumbling. But whoever 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. I am writing to you, little children, because your sins are forgiven for his name’s sake. I am writing to you, fathers, because you know him who is from the beginning. I am writing to you, young men, because you have overcome the evil one. I write to you, children, because you know the Father. I write to you, fathers, because you know him who is from the beginning. I write to you, young men, because you are strong, and the word of God abides in you, and you have overcome the evil one. Do not love the world or the things in the world. If anyone loves the world, the love of the Father is not in him. For all that is in the world—the desires of the flesh and the desires of the eyes and pride of life—is not from the Father but is from the world. And the world is passing away along with its desires, but whoever does the will of God abides forever. Children, it is the last hour, and as you have heard that antichrist is coming, so now many antichrists have come. Therefore we know that it is the last hour. They went out from us, but they were not of us; for if they had been of us, they would have continued with us. But they went out, that it might become plain that they all are not of us. But you have been anointed by the Holy One, and you all have knowledge. I write to you, not because you do not know the truth, but because you know it, and because no lie is of the truth. Who is the liar but he who denies that Jesus is the Christ? This is the antichrist, he who denies the Father and the Son. No one who denies the Son has the Father. Whoever confesses the Son has the Father also. Let what you heard from the beginning abide in you. If what you heard from the beginning abides in you, then you too will abide in the Son and in the Father. And this is the promise that he made to us—eternal life. I write these things to you about those who are trying to deceive you. But the anointing that you received from him abides in you, and you have no need that anyone should teach you. But as his anointing teaches you about everything, and is true, and is no lie—just as it has taught you, abide in him.” (1 John 2:3–27, ESV)
Obedience is the evidence of grace at work in the lives of true believers who know God and keep his word. Those who claim to know him but walk in disobedience are liars. John reminds the readers that love is not a new command, but it is new in the sense that Jesus' addition was to love as he had loved others. The one in darkness is blind and stumbles while hating their brother. John abruptly breaks and speaks to little children, fathers, and young men. He seeks to comfort them by explaining how they are in the faith. The Christian life is forgiveness, fellowship, and fighting for the faith. The Christian still faces temptation and so John reminds them not to love the world. The world is temporal, and therefore, anything desires of flesh can only offer fleeting pleasure. Those that have seceded from the church were never truly a part of the family of God, and this is confirmed by their departure. Many antichrists have come, but the true believer has been anointed by the Holy One and has a knowledge of the truth. Christ is central to Orthodox Christianity so those who would deny the Son and the Father, deny the faith. The things they heard at the beginning of the apostolic witness have not changed, and they must hold fast to those truths. When someone abides in the Father and the Son, they have eternal life. John warns against those that would seek to deceive through new teachings and reminds the Christian that the Holy Spirit teaches and confirms what is true.
It seems that many are looking for a new word and a new teaching, but John reminds us that we must hold fast to the faith once for all delivered to the saints. It may seem redundant, but John tells his readers over and over to remember what they heard from the beginning. Belief and behavior must be harmonious. Love and light are the way of the follower of Jesus while darkness and hate are the paths of the wicked. We must hold fast to the things of God and reject the things of this world because a love for the world indicates that the love of the Father is absent. The real nature of the antichrists was shown by their departure from the faith, sound doctrine, and God's church. Salvation is found in none other than Christ, so any faith that would deny the Father or Jesus Christ is false. Hearts and minds are illuminated to the truth by the Holy Spirit, who will teach, guide and direct us when we abide in him.