And no man has ascended up to heaven, but he that came down from heaven, even the Son of man who is in heaven.
All Commentaries on John 3:13 Go To John 3
Augustine of Hippo
AD 430
After taking notice of this lack of knowledge in a person, who, on the strength of his magisterial station, set himself above others, and blaming the unbelief of such men, our Lord says, that if such as these do not believe, others will: No one has ascended into heaven, but He that came down from heaven, even the Son of man who is in heaven. This may be rendered: The spiritual birth shall be of such sort, as that men from being earthly shall become heavenly: which will not be possible, except they are made members of Me; so that he who ascends, becomes one with Him who descended. Our Lord accounts His body, i.e. His Church, as Himself.
Although He was made the Son of man upon earth, yet His Divinity with which, remaining in heaven, He descended to earth, He has declared notto disagree with the title of Son of man, as He has thought His flesh worthy the name of Sonof God. For through the Unity of person, by which both substances are one Christ, He walked upon earth, being Son of God; and remained in heaven, being Son of man. And the belief of the greater, involves belief in the less. If then the Divine substance, which is so far more removed from us, and could for our sake take up the substance of man so as to unite them inone person; how much more easily may we believe, that the Saints united with the man Christ, become with Him one Christ, so that while it is true of all, that they ascend by grace, itis at the same time true, that He alone ascends to heaven, Who came down from heaven.
But you wonder that He was at once here, and in heaven. Yet such power has He given to His disciples. Hear Paul, Our conversation is in heaven. If the man Paul walked upon earth, and had his conversation in heaven; shall not the God of heaven and earth be able to be in heaven and earth?