“No one has gone up to heaven except the one who came down from heaven, the Son of Man who is in heaven.” John 3:13 (ISV)
Only the omnipresent God can be said to have come down from heaven (John 6:38 – “I came down from heaven”) to become a man (1 Tim. 3:16 - “God was manifested in the flesh”; Heb. 2:14-17 – “Since the children have flesh and blood, he too shared in their humanity … to be made like them, fully human in every way”) in the incarnation while simultaneously remaining unchangeable in the heavens. Hence, God as God has always remained the same (Heb. 13:8 – “Jesus Christ the same, yesterday, today, and forever”; Mal, 3:6) as our unchangeable Heavenly Father, while God with us as man is the human child born and son given who was “made” like all humans are made, “fully human in every way” (Heb. 2:17 - NIV). Wherefore, the divinity of the Son remained “the same (Heb. 13:8)” outside of his virgin begetting as our immutable “Mighty God” and “Everlasting Father” (Isaiah 9:6), while the child born and son given received his true humanity by being “granted life in himself (John 5:26)” inside of his mother by his virgin conception “from out of” (Matthew 1:20- “ek”) the “substance of Being” (Heb. 1:3 – “hypostasis”) of the Father’s Holy Spirit who came down from heaven upon the virgin (Luke 1:35; John 6:38).
John 16:25 and Isaiah 45:14-15 prove that Jesus often used his incarnational titles, “Son of God” and “Son of Man” to veil His true identity as “God with us” as a true man. For if Jesus had openly declared His true identity as “God with us” as a man, he would not have “emptied himself” (Philippians 2:5-9) of his divine rights and privileges as God incarnate. This is precisely what Paul meant when he wrote about Jesus humbling himself and emptying himself in Philippians 2:5-9. Jesus clearly emptied himself and humbled himself throughout his earthly ministry in order to fulfil his mission as the Lamb of God to take away the sins of the world.
Some Trinitarian scholars have pointed out that John 3:13 has variant early manuscripts because it was difficult for the Arians and Semi-Arians who denied the full deity of Christ to state that the person called Jesus Christ could be in heaven and on earth at the same time. According to both Arians and Semi-Arians, Jesus Christ is not the Supreme God because he was created as a heavenly creation before his virgin conception and birth. Since it is unscriptural to affirm that anyone but God alone could be omnipresent everywhere at once (Jer. 23:24; Isaiah 46:9; Mal. 3:6), Arians and Semi-Arians had to deny any scriptures showing the omnipresence of Jesus. Thus, it is very likely that the omission of the words “who is in heaven” (John 3:13) in some manuscripts arose from the influence of the Semi-Arian copyists who were likely more than half of the Christian populace around the time of the Council of Nicaea in 325 (Jaroslav Pelikan wrote, “All the rest saluted the emperor, signed the formula, and went right on teaching as they always had. In the case of most of them, this meant a doctrine of Christ somewhere between that of Arius and that of Alexander (Semi-Arianism)” – The Emergence of the Catholic Tradition, Vol. 1, Pg. 203).
Semi-Arians and Arians would have felt a need to omit the words, “who is in heaven” after “Son of Man” in John 3:13 because they believed that the Son was not the Most High God who alone could be omnipresent. For how could a non-timeless created Son be omnipresent like the Most High God when the Most High God said that “there is none like Me (Isaiah 46:9)?” Origen was one of the many Semi-Arians who denied that the Son of God is the Most High God. Origen wrote, “Grant that there may be some among the multitudes of believers who are not in entire agreement with us, and who incautiously assert that the Savior is the Most High God; however, we do not hold with them, but rather believe Him when He says, ‘The Father who sent Me is greater than I’” (Origen, Contra Celsus 8:14). Wherefore, the Semi-Arians taught that the Son was a lesser god the Son person rather than being the Most High God Himself.
Under John 3:13, Ellicot’s Commentary says, “Which is in heaven. These words are omitted in some MSS., including the Sinaitic and the Vatican. The judgment of most modern editors (not including Westcott and Hort) retains them. It is an instance where it is hard to account for the insertion by a copyist, but where the omission is not unlikely, owing to their seeming difficulty.”
Jesus said in John 3:13 (ISV), “No one has gone up to heaven except the one who came down from heaven, the Son of Man who is in heaven.” Since a created son could not be omnipresent like the Most High God (according to the early Semi-Arians), it is easy to see how Semi-Arian copyists would have omitted the words, “who is in heaven” in John 3:13. Most Trinitarian Commentaries affirm that John 3:13 proves that Jesus is the omnipresent God who never left His divine attributes in the heavens while He simultaneously dwelt on the earth as a man.
The Pulpit Commentary says, “He calls himself ‘Son of man,’” and he claims to have come down from heaven without ceasing to be what he was before.”
Gill’s Commentary says, “even the son of man which is in heaven; at the same time he was then on earth: not that he was in heaven in his human nature… which was proper to him only in his divine nature; for such is omnipresence, or to be in heaven and earth at the same time…”
While most Trinitarian theologians believe that an alleged God the Son was “in heaven and earth at the same time,” a minority of Trinitarian scholars who hold to the kenosis view of Philippians 2:7 actually deny that the Son retained his omnipresence in heaven after the incarnation occurred. Such a view is problematic because the scriptures teach that Jesus as God was in heaven and on earth at the same time (John 3:13; Romans 8:9; Heb. 13:8), and that God can never lose His unchangeable divine attributes (Mal. 3:6; John 8:58; Heb. 13:8) to cease being God for a while in becoming a man to save us. Therefore, those who believe that an alleged God the Son left his omnipresence in heaven during the incarnation are holding a position which is completely untenable.
Oneness theology affirms that the divinity of Jesus is the divinity of “the only true God (John 17:3)” as the Father, whose omnipresence enabled Him to also become a man while simultaneously remaining in the heavens as the unchangeable Father (Mal. 2:10; Mal. 3:6; Isaiah 53:10; Heb. 13:8). If Jesus is not Immanuel as “God with us” as a true man, then why did Jesus say that he came down from heaven and was still in heaven (at the same time – John 3:13; John 6:38) while he dwelt on the earth as a man? Only the omnipresent God can exist, act, and speak in heaven and on earth at the same time because the divine attributes of God cannot be held by anyone created (Isaiah 46:9 “I am God and there is no one like Me”). Therefore, Jesus Christ must be the same divine person as our “only true God (John 17:3)” the “Father” (Ephesians 4:4-6 – “one God and Father above all, through all, and in you all”) who came to save His people from their sins as a true human person (“the man Christ Jesus” – 1 Tim. 2:5).