1 John 4:2-3 says, 'By this you know the Spirit of God: Every spirit that confesses that Jesus Christ has come in the flesh is of God, and every spirit that does not confess that Jesus Christ has come in the flesh is not of God. And this is the spirit of the Antichrist, which you have heard was coming, and is now already in the world.' There were those during the days of the early church who taught that Jesus was not truly human but only appeared to be. This doctrine is called Docetism. According to these people, Jesus didn't really suffer on the cross; He only appeared to be suffering. John wrote these verses to assure us that Jesus Christ was a real human being, not just an appearance. He came in real human flesh. This idea is confirmed in Hebrews 2:14, which says, 'Inasmuch then as the children have partaken of flesh and blood, He Himself likewise shared in the same....'