Concerning the hypostatic union in which one Christ is both God and man, J. C. Ryle wrote: “We should settle it firmly in our minds, that our Savior is perfect man as well as perfect God, and perfect God as well as perfect man. If we once lose sight of this great foundation truth, we may run into fearful heresies.”
In this precious union, the Son of God assumed our human nature to His divinity, though God remained God and man remained man in Him. Consequently, He did not become two persons, but remained one divine Person—the Son of God, Second Person in the holy Trinity. Christ took a human nature to Himself, but never became a “human person.” Thus we must be careful when we speak of Jesus as the God-man, that we underscore that He did not become two persons.
Throughout church history there have been numerous errors that have developed against this doctrine, such as those of the Gnostics, Arians, Socinians, as well as the modern Jehovah’s Witnesses. The early Council of Chalcedon (AD 451) corrected several heretical teachings regarding the essence of the relationship of the natures of Christ. They directed their confession against certain groups. Against Eutychians, the Council stated that Christ’s natures were without mixture and without change. Against Nestorians, they stated that Christ’s natures were without division and without separation. Christ did not have two identities but a strict unity in one Person.
The Belgic Confession of Faith also stated the hypostatic union clearly: “We believe that by this conception, the person of the Son is inseparably united and connected with the human nature; so that these are not two Sons of God, nor two persons, but two natures united in one single person; yet, that each nature retains its own distinct properties” (Article 19).
Once Christ’s divinity assumed humanity, His two natures are never separated. They were never separated during His life or after his death, nor will they be separated in the future. The Belgic Confession continues: “These two natures are so closely united in one Person that they were not separated even by His death. Therefore that which He, when dying commended into the hands of His Father, was a real human spirit, departing from His body. But in the meantime the divine nature always remained united with the human, even when He lay in the grave. And the Godhead did not cease to be in Him, any more than it did when He was an infant, though it did not so clearly manifest itself for a while” (Article 19).
Many Christians today have trouble applying this truth to themselves with profit. But the union of Christ’s natures in one Person should be very sweet to a Christian’s soul since the hypostatic union accords with the believer’s mystical union with Christ.