In this universe there is a unique person, who alone is both God and man. Because of Him God is no longer so distant that we cannot know Him, nor so abstract that we cannot experience Him. In this unique person, God and man have been brought together and have become one. Through Him the divine nature has been manifested among men and has been made available to man that man may partake of it (2 Pet. 1:4); through Him the human nature has been uplifted to the eternal plane that God may be manifested through humanity forever. This unique person is Christ Jesus the Lord. He is altogether wonderful and enjoys many statuses as both God and man. Yet when we focus on just three of His statuses, we discover that He is God become man for our enjoyment and for His expression for eternity. This we see when we consider Christ as the only begotten Son of God, as the Son of Man, and as the firstborn Son of God.
Our understanding of God is necessarily based solely on the Bible, for the Bible is the unique record given to man by God concerning Himself. According to the revelation contained in both the Old and New Testaments, the two sections of the Bible, there is one God in this universe, and this God is triune; that is, He is at the same time one and three. Our rational minds will suggest that there are three Gods, but the pure revelation of the Scriptures tells us that this is not so. God is one (Deut. 6:4; 1 Cor. 8:4), and yet He is the Father, the Son, and the Spirit (Matt. 28:19; 2 Cor. 13:14). The Father is completely God, the Son is completely God, and the Spirit is completely God. The Three are not at all separate, for They mutually indwell one Another; but They are certainly distinct, as Their names Father, Son, and Spirit indicate. The Father is the source, the Son is the expression, and the Spirit is the transmission in the Godhead.
The Bible calls the Second in the Godhead the only begotten Son of God (John 1:14, 18; 3:16, 18; 1 John 4:9). This wonderful title tells us much about Christ. As the only begotten Son, He is of the same essence with the Father and the Spirit. All the fullness of the Godhead dwells in Him (Col. 2:9); that is, He possesses the full essence of God with all its unique attributes. He is fully and perfectly God. When the Bible refers to Him as the only Begotten, it does not mean that at some point in eternity past He was begotten of God and that there was a time when He did not exist; rather, He is eternally God (Heb. 1:12; 7:3). His begetting refers not to an event but to an eternal relationship to the Father: The Father is the eternal source of the Son, and the Son is the eternal expression of the Father. Before time and before creation, Christ was eternally with God and Christ was eternally God (John 1:1). In the Godhead He alone expresses God, for He is the only begotten Son of God.
Although God is outside of time, one day He entered His creation and became a man in time. Consider how marvelous it is that the eternal God became a man. And He was truly man. He was begotten in the womb of a human virgin (Matt. 1:20) and was born as a genuine human infant. Yet He was still the perfect and complete God. Matthew writes: “Now all this has happened so that what was spoken by the Lord through the prophet might be fulfilled, saying, ‘Behold, the virgin shall be with child and shall bear a son, and they shall call His name Emmanuel’ (which is translated, God with us)” (1:22-23). Jesus Christ is our Emmanuel: He is God with us; He is God in man. By His incarnation, Christ took upon Himself our human nature. He is still the eternal God, possessing the divine essence with the divine nature, but He is also the perfect man, possessing the human nature. Hence, in Christ there is both the divine and the human.
In His incarnation, Christ is called the Son of Man (Matt. 12:8, 40; Mark 8:31, 38; Luke 19:10; 22:69; John 3:13; 6:53; 13:31). This is another wonderful title of Christ, for it indicates that Christ is a genuine man and the perfect representative of our race. Although He partook of blood and flesh (Heb. 2:14) as we do, He does not have the sinful element that we have —He is without sin (Heb. 4:15; 2 Cor. 5:21). Throughout His living on earth, He committed no sin (1 Pet. 2:22). Hence, as the Son of Man, He is the perfect man.
Christ, then, was the only begotten Son of God, the complete God, in His divinity; and in His humanity He was the Son of Man, the perfect man. This wonderful God-man lived a full, divinely human life on earth, then went to the cross to die for our sins. As the Son of Man, He was able to suffer the punishment for the sins of all mankind (Gal. 1:4; Rom. 5:8); and as the Son of God, He was able to obtain, through the Spirit, an eternal redemption for us (Heb. 9:12). Only this unique person, because He is both divine and human, could accomplish such an eternal redemption.
After His death on the cross, Christ was raised from the dead (1 Cor. 15:4). Only His humanity had died; but by virtue of His divinity, His humanity was resurrected from the grave. On the morning of His resurrection, He declared that His disciples were now His brothers and that His Father was now their Father (John 20:17). By this He made clear that we who believe in Him are now the sons of God (Gal. 3:26; John 1:12; Rom. 8:14). Through His resurrection He became the firstborn Son of God (Rom. 8:29), and we who believe in Him became the many brothers, the many sons of God (Heb. 2:10; 1 Pet. 1:3).
Formerly, before His incarnation, Christ was the only begotten Son of God. This refers to His divinity and to His identity in the Godhead. He is eternally the only begotten Son of God, and as such, He can never have brothers. Yet, the Scriptures declare that He is also the Firstborn among many brothers (Rom. 8:29). This refers to Him in resurrection, when He was glorified to be the Son of God both in His divinity and in His humanity. The apostle Paul spoke of this: “God has fully fulfilled this promise to us their children in raising up Jesus, as it is also written in the second Psalm, ‘You are My Son; today I have begotten You’ ” (Acts 13:33). When Christ was resurrected, His humanity was begotten to be the Son of God as well. In His divinity He was already the only begotten Son of God, but through His resurrection His humanity became the Son of God also, and the way was opened for us to become the many sons of God. In another place Paul writes that Christ “was designated the Son of God in power according to the Spirit of holiness out of the resurrection of the dead, Jesus Christ our Lord” (Rom. 1:4). As the only Begotten, Christ has never needed to be designated the Son of God, but through His resurrection the humanity of Christ was designated the Son of God in power. Now He is the Son of God both in His divinity and in His humanity. His humanity has been “Sonized” and uplifted to the eternal plane. Today Christ as the only begotten Son in His divinity and as the Son of Man in His humanity is the firstborn Son of God.
The truth concerning the person of Christ is the good news of our salvation. The eternal only begotten Son of God became the Son of Man, who died for our sins and was raised for our acceptance before God (Rom. 4:25); and in resurrection this God-man became the firstborn Son of God, making us who believe in Him His many brothers, the many sons of God. We, who once were sinners, can become the sons of God by repenting of our sins and believing in Christ. This is His salvation to man.