Confessing that Jesus Christ came in the flesh is foundational, and II John 7 and I John 4:2-3 call anyone who denies it a deceiver and antichrist. The reasoning begins with Romans 6:23: sin is paid for only by death, and humanity's sin is so great that only the death of the Creator Himself could cover it. Yet the Creator is eternal, spirit, and life itself, so He could die only by voluntarily setting aside much of His glory and prerogatives to become a real man while retaining His character and the Holy Spirit. Hebrews 2, 5, and 10, Philippians 2:5-8, Galatians 4:4, and I Timothy 3:16 present this as the only way to satisfy God's justice and make Him a merciful High Priest and propitiation. John 1:14, the birth accounts in Matthew and Luke, the "Seed of the woman" in Genesis 3:15, and Immanuel in Isaiah 7:14 show Him as both Son of God and Son of Man, born of a woman. I Peter 1 points to His blood, visibility, and death as marks of true humanity, and I John 1:1-3 gives eyewitness testimony of seeing, hearing, and touching Him. John wrote against Gnostic and Docetic teaching that separated the spiritual Christ from the human Jesus. Denying His coming in the flesh nullifies His sacrifice, though the spirit of antichrist more broadly includes any false conception of Christ. Because He was fully human and also God, believers have forgiveness and eternal life.

Jesus Christ, coming in the flesh, is a profound reality that shaped the understanding of His identity and mission. Many were confused about who He was, with some believing Him to be John the Baptist, Elijah, Jeremiah, or another prophet, while others questioned His sanity, saying He had a demon or was out of His mind. Despite this, Peter declared, "You are the Christ, the Son of the living God," though even he did not fully grasp Jesus' true purpose at the time. The public was astonished at His teaching, for He spoke with authority unlike the scribes, and the educated elite marveled at His wisdom, though they mocked Him, unsure of His origins. The scriptures foretold His coming, and it became clear that Jesus Christ was indeed the Word made flesh. In the beginning, the Word was with God and was God, co-existing eternally with the Father, yet sent by Him in a position of obedience. The Word became completely flesh, not merely inhabiting a body but truly human, as we are, with life residing in His blood. He was both human and divine, God manifest in the flesh, partaking of flesh and blood in the same manner as humanity, so that He might die. He did not come in the nature of angels but took on human nature at birth, tempted in all points as we are, suffering as we do, resisting the pull of human nature. Jesus, as flesh, had to die to fulfill God's plan, shedding His blood, not a spirit, to save us from our sins. His life, residing in His blood, was poured out on the stake, given for us. He was completely dead for three days and nights, not merely a body dying but Christ Himself, the Eternal, changed into mortal flesh, subject to death. God the Father raised Him from the dead, restoring Him to immortality, no longer human but a living Savior. His death, as our Maker, was of greater value than the sum of all human lives, paying the penalty for all sins. Thus, every spirit that confesses Jesus Christ is come in the flesh is of God, affirming the reality of His human existence and sacrifice.

Jesus Christ came in the flesh when the Word became flesh and dwelt among men. This Spirit Being and Creator came to be flesh while remaining God at all times. He assumed human nature without becoming wholly fused with it and without giving up His identity as God. He experienced human limitations such as weariness, thirst, dependence on blood for life, the possibility of death, and emotions including groaning and weeping. He remained God throughout His human life, in the grave, and after resurrection. The apostles examined Him with care and beheld His glory as the only begotten of the Father, full of grace and truth.