1 John 4:1 Beloved, do not believe every spirit, but test the spirits to see whether they are from God, because many false prophets have gone out into the world. 2 By this you know the Spirit of God: every spirit that confesses that Jesus Christ has come in the flesh is from God; 3 and every spirit that does not confess Jesus is not from God; this is the spirit of the antichrist, of which you have heard that it is coming, and now it is already in the world.

Although the details are few, we know that some kind of disruption occurred that resulted in some who had professed to be Christians leaving the group to which John is writing. John indicates that this caused a great amount of stress. Based on the verses just read, another source of danger was false teaching.

It is generally agreed that John is referring to self-proclaimed prophets (or teachers) when he issues the warning that we see in verse one. The threat was significant, according to his description: “many false prophets have gone out into the world.” This meant that these believers had to be extremely careful regarding their sources of instruction. The only thing that could be done is what John advises, namely, “test the spirits to see whether they are from God.”

The word translated “test” (dokimazo) means “to scrutinize something to determine its authenticity.” The apostle is telling his readers to examine the message of those who claim to be speaking for God and compare what they hear with what the apostles had already imparted. John infers that such an examination can lead to a definitive conclusion regarding truthfulness.

The means of testing is not left up to the people, however. John tells them what standard to apply when they assess the proclamations they encounter. In the second verse, he reveals the key to identifying the prophets of God: “every spirit that confesses that Jesus Christ is come in the flesh is from God.” This tells us, it appears, that the fundamental issue being debated had to do with the nature of Jesus Christ.

In his typical style, John is blunt in his assessment of these false prophets: “this is the spirit of the antichrist.” Already, he adds, these enemies of the gospel are at work in the world seeking to oppose the preaching of the good news and keep people from finding deliverance in Christ.

The gospel message included this declaration that the Savior was not a mere man, but was God in the flesh. This fact meant that Christ’s sacrifice was infinitely worthy and could, therefore, atone for our sins. The death of a man could not provide what was required, but the death of God, as it were, was more than sufficient to satisfy the demands of God’s justice. Therefore, those who were proclaiming that Jesus Christ was not God in the flesh had to be rejected.