Let me begin with some words from Pope St. Leo the Great about today’s solemnity:
Dearly beloved, through all this time which elapsed between the Lord’s resurrection and ascension, God’s providence had this in view, to teach his own people and impress upon their eyes and their hearts that the Lord Jesus Christ had risen, risen as truly as he had been born and had suffered and died.
Hence, the most blessed apostles and all the disciples, who had been both bewildered at his death on the cross and backward in believing his resurrection, were so strengthened by the clearness of the truth that when the Lord entered the heights of heaven, not only were they affected with no sadness, but they were even filled with great joy.
Truly, it was great and unspeakable, that cause of their joy, when in the sight of the holy multitude the nature of mankind went up: up above the dignity of all heavenly creatures, to pass above the angels’ ranks and to rise beyond the archangels’ heights, and to have its uplifting limited by no elevation until, received to sit with the eternal Father, it should be associated on the throne with his glory, to whose nature it was united in the Son.
As St. Leo says, human nature went to heaven. The divine nature, in the person of the Son, came down from heaven, as we recite in the Creed. And so in the Ascension we see a completion of that journey, as the divine Son brings his human nature with him to glory.
This is more than just human nature, though. In another sermon, St. Leo observes that, when our Lord says in St. Mark’s Gospel to preach the gospel to “all creatures,” this is shorthand for all humanity, because in human nature is contained the sum of all created things. We share a spiritual creation with the angels. We share a physical creation with plants and animals. And so for a human being to enter the highest heaven means nothing less than that heaven and earth are now permanently joined.
Catholics talk about getting to heaven when we die, but it is also the firm teaching of the Church that the beatific vision, the life of heaven, is available here and now. What happens when we die, and when we eventually received our glorified bodies, is not that we somehow exit creation and start floating in spiritual nothingness. It is simply that we will be able to perfectly and fully live a human life freed from the constraints of our mortality and the blindness caused by sin and ignorance.
In the Ascension we see, even more clearly than in the Resurrection, that salvation doesn’t mean salvation from created life or from human nature. It is not some kind of Buddhist self-dissolution into the ocean of being. It means salvation in and through our human nature.
And so when we approach the sacraments, we are opening up the veil that clouds our sight to the life of heaven that is always ever before us. If we are in Jesus, and he is in us, we are in heaven. And our task is not to leave where we are—nor to “gaze up into heaven” as the disciples do until the angel shocks them back to the present—but to be where we are and seek the heavenly life now. If we wait around to go to heaven when we die, it will probably be too late.