It makes no sense to celebrate the ascension of Christ unless we understand the difference between departure and disappearance.
Departure results in absence.
Disappearance inaugurates a hidden presence.
Think about it. Christ is here on earth with us and will never leave us, because His spiritual presence is more intensive and extensive than His physical presence ever could have been. For our own good He disappeared visibly, so we could find Him present invisibly, any time, anywhere.
At His ascension Christ became invisible, was fully glorified in His humanity, and began sharing the infinite power of the Father as Theánthropos, God-Man.
Because of this, He is closer to us than He ever was before.
Far from abandoning us and leaving us orphans [John 14.18], He acquired the very influence and boundless efficacy that enables Him to fill everything with His presence. [Ephesians 4.10].
Fr. Louis Evely