“Gnosis” is one of the Greek words for “knowledge.” We have seen it, along with its related verb forms, crop up all over 1 John. “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” (2.13). “The reason why the world does not know us is that it did not know him” (3.1). “No one who abides in him keeps on sinning; no one who keeps on sinning has either seen him or known him” (3.6). This is just a small sample.

“Gnosis” was also the basis of Christianity’s first and greatest heresy, gnosticism. More than a heresy, gnosticism was a whole set of heresies. What tied all of them together was “knowledge,” always hidden or mystical in nature. Gnosticism appealed, and still appeals, to people who make an idol of knowledge. For such people, knowledge is a matter of status and prestige, hence the gnostic focus on secret knowledge. Such knowledge was only accessible to a select few, those who were clever enough, smart enough, and well-connected enough to access it. Some gnostics claimed to receive visions from angels or from God Himself. All of it was an attempt on the gnostics’ part to feel and act superior to those around them.

The gnostics did not claim to belong to a different faith. They professed themselves to be Christians—better Christians, in fact, than the apostles, because they claimed to possess a greater knowledge than what the apostles had revealed. Their heresy was an attempt to take over the church and remake it in their own image.

Gnosticism threatened the early church, not only because it was false, but because it was also popular. Antinomian (“anti-legal”) gnosticism taught that Christians are free from any kind of moral obligation; sins committed in the flesh could have no effect on the spirit. You can imagine how popular this worldly heresy became. People flocked to it, thinking all the while that they were Christians in good standing with the Lord. John rejects such false knowledge: “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” (1 Jn 2.4-6).

The most prominent gnostic heresies all claimed to have superior knowledge about the nature of Jesus, because the mystery of the Incarnation is insufferable to the person whose god is knowledge. The Incarnation is a mystery; it cannot be understood, reasoned through, or arrived at independently; it can only be confessed as it is revealed by God. The gnostics could not make themselves lords over the Incarnation, so they modified it or even denied it outright.

Docetism, for example, is the heresy that denies that Jesus appeared in the flesh. The docetists believed that Jesus’ physical body was an illusion and that He was pure spirit. Because of this, they also denied the Crucifixion, claiming that it, too, was an illusion. They also refused to take the Lord’s Supper, because the bread and cup represent Christ’s body and blood. John explicitly condemns docetism in our sermon text this morning: “By this you know the Spirit of God: every spirit that confesses that Jesus Christ has come in the flesh is from God, and every spirit that does not confess Jesus is not from God. This is the spirit of the antichrist, which you heard was coming and now is in the world already” (1 Jn 4.2-3).

Other heresies denied Jesus’ divinity. Though the most prominent such heresy, Arianism, didn’t arise until the fourth century, its prototypes certainly existed earlier. John is at pains to establish the divinity of Christ and condemn those who deny it. “The life [Jesus Christ] was made manifest, and we have seen it, and testify to it and proclaim to you the eternal life, which was with the Father and was made manifest to us…. 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” (1 Jn 1.2; 2.22-23).

Gnosticism is the enemy that permeates every passage of 1 John. John writes about knowledge at every turn, because he recognizes the threat the gnostics pose to the Church. Besides being false teachers, they are schismatics (“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,” 1 Jn 2.19). 1 John exposes gnosticism for the fool’s errand it is. The gnostics have separated themselves not only from the Church but from the Father and the Son. They have traded away eternal life for their vanity. Ironically, the gnostics know nothing: they are outside of the Faith of Jesus Christ.

May we all abide in the true Faith presented by the apostles.