1 John 4:6

We are of God; he that knoweth God heareth us; he that is not of God heareth not us. Hereby know we the Spirit of Truth and the spirit of error.

The spirit which the apostle has above called the spirit of Anti-Christ is here identified with the spirit of this world, with the spirit that works in the children of disobedience, Ephesians 2:2. This is shown by the contrast: You are of God, little children, and you have conquered them, because greater is He that is in you than he that is in the world. The believers belong to God, they are the children of God, having been born again out of the water of Baptism and the Spirit. Therefore they not only have the knowledge necessary to examine and test the spirits, but they also have the ability, the power to withstand their allurements, to conquer them. All anti-Christian temptation is powerless against the strength of God that lives in the believers. For though Satan, the prince of darkness and the father of lies, is in the false teachers, lives in them, actuates them, yet God, who lives in us, who is our Strength and our Refuge, is greater and stronger than the devil with all his evil angels.

The apostle adds another reason for carefully examining the claims and for guarding against the evil influence of the false teachers: They are of the world, therefore they talk as of the world, and the world listens to them. No matter what their pretense and their glamour, the false teachers belong to the world, they have the world's manner and mind. This is shown also in their talking, in their teaching and preaching, for its substance is not divine and leading to godliness, but it is inspired by the world, by its manner of thinking and acting. False teachers usually have messages that tickle the itching ears of their hearers. The children of the world will gladly hear them, the world receives their doctrines with enthusiasm. It is an almost unfailing criterion: if a certain preacher is widely advertised and acclaimed as a prophet for our times, he has probably managed to accommodate the old Scriptural language to some of his own philosophy in denying the fundamentals of the Bible. Witness the so-called Christianity of the social gospel.

Of himself and of his co-workers John writes, by way of contrast: We are of God; he that knows God hears us, he that is not of God does not hear us; in this you can recognize the Spirit of Truth and the spirit of error. The apostles were not only converted Christians, true believers, but they were also messengers, ambassadors of God. Thus all true preachers, whose call is from God, are messengers of God, no matter how lowly they may be in the sight of the world. True Christians show their knowledge of God, their faith in Him, by listening to these messengers, by yielding due obedience to the Gospel-message which they bring. They are thereby distinguished from those that know nothing of regeneration and want to know nothing of the Gospel of salvation. The attitude of men toward the true preachers of the Gospel is a reliable indication of their own spiritual state, whether they are still governed by the spirit of error, of falsehood and deceit, or whether they have opened their hearts to the Spirit of Truth and have come to faith.