1 John 4:2

By this you know the Spirit of God: every spirit that confesses that Jesus Christ has come in the flesh is from God;

1 Corinthians 12:3

Therefore I make known to you that no one speaking by the Spirit of God says, “Jesus is accursed”; and no one can say, “Jesus is Lord,” except by the Holy Spirit.

John 1:14

And the Word became flesh, and dwelt among us, and we saw His glory, glory as of the only begotten from the Father, full of grace and truth.

John 16:13-15

But when He, the Spirit of truth, comes, He will guide you into all the truth; for He will not speak on His own initiative, but whatever He hears, He will speak; and He will disclose to you what is to come.

1 Timothy 3:16

By common confession, great is the mystery of godliness:
He who was revealed in the flesh,
Was vindicated in the Spirit,
Seen by angels,
Proclaimed among the nations,
Believed on in the world,
Taken up in glory.

1 John 2:23

Whoever denies the Son does not have the Father; the one who confesses the Son has the Father also.

1 John 4:3

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.

1 John 5:1

Whoever believes that Jesus is the Christ is born of God, and whoever loves the Father loves the child born of Him.

Treasury of Scripture Knowledge

Summary

Hereby know ye the Spirit of God: Every spirit that confesseth that Jesus Christ is come in the flesh is of God:

General references

Bible References

Come

1 John 4:3
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.
John 1:14
And the Word became flesh, and dwelt among us, and we saw His glory, glory as of the only begotten from the Father, full of grace and truth.
1 Timothy 3:16
By common confession, great is the mystery of godliness:
He who was revealed in the flesh,
Was vindicated in the Spirit,
Seen by angels,
Proclaimed among the nations,
Believed on in the world,
Taken up in glory.

General references

Deuteronomy 18:21
You may say in your heart, ‘How will we know the word which the Lord has not spoken?’
John 8:47
He who is of God hears the words of God; for this reason you do not hear them, because you are not of God.”