In the church calendar, May 5 was Ascension Day this year. The scriptural passage that speaks most directly about the Ascension of Jesus to heaven is in Acts 1:1-11....
C. S. Lewis comments on the Ascension in his book Miracles where he writes...
In the first book, Theophilus, I wrote about all that Jesus did and taught from the beginning until the day when he was taken up to heaven, after giving instructions through the Holy Spirit to the apostles whom he had chosen. After his suffering he presented himself alive to them by many convincing proofs, appearing to them during forty days and speaking about the kingdom of God. While staying with them, he ordered them not to leave Jerusalem, but to wait there for the promise of the Father. “This,” he said, “is what you have heard from me; for John baptized with water, but you will be baptized with the Holy Spirit not many days from now.”
So when they had come together, they asked him, “Lord, is this the time when you will restore the kingdom to Israel?” He replied, “It is not for you to know the times or periods that the Father has set by his own authority. But you will receive power when the Holy Spirit has come upon you; and you will be my witnesses in Jerusalem, in all Judea and Samaria, and to the ends of the earth.” When he had said this, as they were watching, he was lifted up, and a cloud took him out of their sight. While he was going and they were gazing up toward heaven, suddenly two men in white robes stood by them. They said, “Men of Galilee, why do you stand looking up toward heaven? This Jesus, who has been taken up from you into heaven, will come in the same way as you saw him go into heaven.”
... the story of the Ascension cannot be separated from that of the Resurrection. All the accounts suggest that the appearances of the Risen Body came to an end; some describe an abrupt end about six weeks after the death. And they describe this abrupt end in a way which presents greater difficulties to the modern mind than any other part of Scripture. For here, surely, we get the implication of all those primitive crudities to which I have said that Christians are not committed: the vertical ascent like a balloon, the local Heaven, the decorated chair to the right of the Father’s throne. ‘He was caught up into the sky (ouranos)’, says St Mark’s Gospel ‘and sat down at the right hand of God’. ‘He was lifted up’, says the author of Acts ‘and a cloud cut Him off from their sight’.
It is true that if we wish to get rid of these embarrassing passages we have the means to do so. The Marcan one probably formed no part of the earliest text of St Mark’s Gospel: and you may add that the Ascension, though constantly implied throughout the New Testament, is described only in these two places. Can we then simply drop the Ascension story? The answer is that we can do so only if we regard the Resurrection appearances as those of a ghost or hallucination. For a phantom can just fade away; but an objective entity must go somewhere—something must happen to it. And if the Risen Body were not objective, then all of us (Christian or not) must invent some explanation for the disappearance of the corpse. And all Christians must explain why God sent or permitted a ‘vision’ or ‘ghost’ whose behaviour seems almost exclusively directed to convincing the disciples that it was not a vision or a ghost but a really corporeal being. If it were a vision then it was the most systematically deceptive and lying vision on record. But if it were real, then something happened to it after it ceased to appear. You cannot take away the Ascension without putting something else in its place.
The records represent Christ as passing after death (as no man had passed before) neither into a purely, that is, negatively, ‘spiritual’ mode of existence nor into a ‘natural’ life such as we know, but into a life which has its own, new Nature. It represents Him as withdrawing six weeks later, into some different mode of existence. It says—He says—that He goes ‘to prepare a place for us’. This presumably means that He is about to create that whole new Nature which will provide the environment or conditions for His glorified humanity and, in Him, for ours. The picture is not what we expected—though whether it is less or more probable and philosophical on that account is another question. It is not the picture of an escape from any and every kind of Nature into some unconditioned and utterly transcendent life. It is the picture of a new human nature, and a new Nature in general, being brought into existence. We must, indeed, believe the risen body to be extremely different from the mortal body: but the existence, in that new state, of anything that could in any sense be described as ‘body’ at all, involves some sort of spatial relations and in the long run a whole new universe. That is the picture—not of unmaking but of remaking. The old field of space, time, matter, and the senses is to be weeded, dug, and sown for a new crop. We may be tired of that old field: God is not.