1 John 4:2

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

Hereby know ... Spirit of God - whether He be or not in those professing to be moved by Him Hereby know ... Spirit of God - whether He be, or not, in those professing to be moved by Him.

Every spirit - i:e., Every teacher claiming inspiration by THE HOLY SPIRIT.

Confesseth - the truth is taken for granted. Man is required to confess it openly, as in teaching.

Jesus Christ is come in the flesh - a twofold truth confessed: that Jesus is the Christ; and that He is come [ eleeluthota (G2064), perfect; not a mere past historical fact, but present, and continuing in its blessed effects] in the flesh ('invested with flesh;' not with a seeming humanity, as the Docetae afterward taught). He therefore was previously something far above flesh. His flesh implies His death for us; for only by assuming flesh could He die (as God He could not, Hebrews 2:9; Hebrews 2:16), and His death implies His LOVE for us (John 15:13). To deny the reality of His flesh is to deny His love, and so cast away the root which produces true love on the believer's part (1 John 4:9; 1 John 4:19). Rome, by the doctrine of the Virgin's immaculate conception, denies Christ's proper humanity.