That Confesses

1 John 4:1-3 (ESV Strong's)

1 Beloved, do not believe every spirit, but test the spirits to see whether they are from God, for 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, which you heard was coming and now is in the world already.

Jesus has come in the flesh, first in flesh of His own, and now in the flesh of all who would receive Him. When we confess Him with our mouths, we are acknowledging that His Spirit has come into our flesh and “God is with us.” By our words the word of God is fulfilled.