"Many false prophets have gone out into the world." In John's day, there were teachers going about doing certain signs, giving predictions of things to come, and performing miracles. John writes, "Do not believe these spirits -- until you have tested them."
"Test them, John encourages" because behind the false prophet is an evil spirit. On the other hand, there is the Holy Spirit of truth, the Spirit of love. And just as God speaks through men, so evil spirits speak through men. Following the Lord Jesus Christ means we accept what he says is the explanation of the power behind evil in the world. John says, "test these spirits, try them." Lay them alongside a measuring stick, and if they do not match the measuring stick of God's truth, throw them out.
There are two parts to the test.
First, the test that the Son of God came incarnate which means that He was 100% man and 100% God. In 1 John 4:2 we read, "...every spirit which confesses that Jesus is Christ, come in the flesh, is of God...". It was when he was born as a babe in Bethlehem and grew up in Nazareth that he bore the human name of Jesus. The teaching of Scripture is that this Jesus of Nazareth, this historical Jesus, is the predicted Messiah of the Old Testament. God, himself, came into human history. This is the Spirit of truth. Jesus makes this claim about himself, In John 10, he says, "Truly, truly, I say to you, he who does not enter the sheepfold by the door but climbs in by another way, that man is a thief and a robber; but he who enters by the door is the shepherd of the sheep. To him the gatekeeper opens; the sheep hear his voice, and he calls his own sheep by name and leads them out," {John 10:1-3}.
Then he says,
"I am that good shepherd. I came in the predicted way, the way the prophets announced. I was born in the right place, at the right time, in the right way. I came exactly as it was announced. I am the door; I am the shepherd of the sheep," (John 10:14)
Now he who confesses this, John says, is of the truth, is of God. But anyone who teaches otherwise, that Jesus Christ is not God come incarnate, is not of God. Do not listen to him, pay no attention to him. Regardless of how amazingly he talks, he is not of God. He is of the spirit of error, the spirit of antichrist, that has already gone out into the world. This is the most important doctrine which can never be compromised. It is the one thing that is fundamental to all Christian faith. He came as a man, humbled himself, and became obedient unto the death of the cross.
Now the second thing that John brings out here is that this must not only be acknowledged as a historical fact, but it must order the life of the one who teaches it. This word "confess" in v.2 means to commit your life to something. In this case, to commit oneself to the truth. It is more than a mere acknowledgment or a profession that this is true; it is a commitment. It means to actually trust this great historic person. Anyone who does not actually trust in this truth, and live by it, do not listen to them either.
Then we must ask: Do you follow him? Do you live by this?
John says if they do not confess that Jesus is the Christ, come in the flesh, this is the spirit of error, of antichrist.
