"It may seem absurd to say that he 'is in heaven' while he still lives on earth. If it is answered that this is true about his divine nature, then this expression would mean something else—-namely, that while he was man he was 'in heaven.' I could point out that no place is mentioned here and that only Christ is distinguished from everybody else as far as his state is concerned, since he is the heir of the kingdom of God, from which the whole human race is banished. However, as very frequently happens, because of the unity of the person of Christ, what correctly applies to one of his natures is applied to another of his natures, and so we need seek no other solution. So Christ, who 'is in heaven,' has clothed himself in our flesh, so that by stretching out his brotherly hand to us he may raise us to heaven with himself."
—John Calvin, John, Crossway Classic Commentaries, eds. Alister McGrath and J. I. Packer (Wheaton, IL: Crossway, 1994), 74-75.
"For even if the Word in his immeasurable essence united with the nature of man into one person, we do not imagine that he was confined therein. Here is something marvelous: the Son of God descended from heaven in such a way that, without leaving heaven, he willed to be borne in the virgin's womb, to go about the earth, and to hang upon the cross; yet he continuously filled the world even as he had done from the beginning!"
—John Calvin, Institutes of the Christian Religion, ed. John T. McNeill, trans. Ford Lewis Battles, 2 vols., (Philadelphia: Westminster, 1960), 1:481.