Book of 1 John Chapter 4 Vs. 6

 Test the Spirits

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."

he that knoweth (ὁ γινώσκων)

Lit., the one knowing: he who is habitually and ever more clearly perceiving and recognizing God as his Christian life unfolds. The knowledge is regarded as progressive and not complete. Compare Phlp. 3:12, and He who is calling ὁ καλῶν, 1Thes. 5:24 also ὁ ἀγαπῶν he that loves (1Jhn. 4:7).

Hereby know we... The Holy Spirit is the Spirit of truth (John 14:16-17; 15:26; 16:13) and the spirit of error is Satan (2Cor. 4:4; 11:14-15; Mat. 13:19; 1Tim. 4:1-2). The Old Testament and New Testament are the sole standards by which all teaching is to be tested. In contrast, demonically inspired teachers either reject the teaching of God's word or all elements to it (2 Cor. 4:2; Rev. 22:18-19).

Hereby (ἐκ τούτου)

Not the same as the common ἐν τούτῳ (1Jhn. 4:2). It occurs only here in the Epistle. Ἑν τούτῳ is in this: ἐκ τούτου from this. The former marks the residing or consisting of the essence or truth of a thing in something the apprehension of which conveys to us the essential nature of the thing itself. The latter marks the inference or deduction of the truth from something, as contrasted with its immediate perception in that something. Rev., by this.

the spirit of error (τὸ πνεῦμα τῆς πλάνης)

The phrase occurs nowhere else in the New Testament. Compare πνεύμασι πλάνοις misleading spirits, 1Tim. 4:1.

Christians will receive this message that John and the other true apostles are bringing. Christians have ears to hear, and they hear.

We should take as our guideline that whoever knows God listens to us; whoever is not from God doesn't listen to us; like Yochanan, we can be satisfied with that.

The pronouns which begin 1Jhn. 4:4-6 You… They, and We are emphatic in the original and evidently mark off three groups: the readers, the antichrists, and the apostles. Each one who can be described as from God i.e., actuated and influenced by God and thus knows God listens to the apostolic voice. In the history of the church, apostolic doctrine has always been the means by which the Holy Spirit of truth and the spirit of falsehood can be effectively distinguished. True Christianity is apostolic Christianity.