1 John 4:2,3 - Every spirit that confesses Christ

4:2

John now gives a test. Now, this is not the only test, and will not be relevant in all cases. Earlier John has given tests in terms of believing in Christ, loving one another, obeying God. We now get a clear doctrinal test. In the early church heresies tended to deny the full humanity of Christ, whereas today false teachers are much more likely to deny the full deity of Christ. So the test that John gives here, the one relevant to the sort of false teaching his readers were likely to encounter, is whether or not someone acknowledged that Jesus Christ came in the flesh from God. The Holy Spirit will testify to the full deity and full humanity of Christ, He bears witness to Christ. Jesus is the Christ, the Messiah, sent by God,  He is and was fully human.

4:3

As John frequently does in this letter, he then states the antithesis. In the previous verse he has said that the Spirit of God confesses that Jesus is the Christ come in the flesh, the converse is that every spirit that does not confess Christ is not from God. In earlier chapters he has said that anyone who denies Christ does not belong to the Father, now he says that anyone that denies Christ is not inspired by the Spirit. The whole focus of God’s work is on Jesus Christ. John had warned his readers earlier that there would be deceiving spirits and false teachers.  They are inspired by the spirit of antiChrist.