I have Fr Philip Endean S.J. to thank for highlighting something about the Ascension that I think many of us overlook, though he is not responsible for my interpretation of his original remarks (see https://www.thinkingfaith.org/articles/20120521_1.htm).
We tend to think of the post-Resurrection appearances of Jesus as being somehow a bit more ordinary life tacked on after his death on the Cross before his final disappearance into heaven. Yet, as we all know, the Risen Christ lives for evermore with the newness of life the Resurrection signifies — and he is with us always, to the end of time. The Ascension is not a parting or a disappearance but a fulfilment. An Orthodox friend once commented that our Western feast of Christ the King always struck him as unnecessary because the Ascension marked Christ’s transformation of our limited, earthly notions of power into the limitless, heavenly reality. As a feast of transformation rather than of parting, the Ascension makes perfect sense. This is the day when all our old ideas are shown to be inadequate. Christ does not abandon us or ‘leave’ us. He changes for ever our understanding of presence and makes possible that coming of the Holy Spirit at Pentecost which will make all things new.