One could say that what is celebrated under the banner of the Ascension of Jesus into heaven is hope. Christian hope. A hope that is neither in a method nor in a procedure.
It is a hope specifically in a person. That person is Jesus Christ who. Through his resurrection from the dead, demonstrated that his lordship, his kingdom reached far beyond the boundaries of the created universe and all of what we refer to as natural, including death.
The Church's liturgy celebrates the intimate relationship that exists between Jesus' passion, death, resurrection, ascension and Pentecost. Together they constitute the Pascal mystery.
The preface of today's mass sums it all up.
"In his risen body he plainly showed himself to his disciples and was taken up to heaven in their sight to claim for us a share in his divine life."
The disciples knew that from that moment he was most probably gone for ever from their sight.
You would think that given all the circumstances, especially political, that this would be a time of deep sorrow, of painful loss and fearful abandonment. A time when all their false hopes for the future would be seen to have been futile.
But, No! Luke tells us that they returned to Jerusalem with great joy!
Why? Because, says Luke, "Jesus had opened up their minds to understand the Scriptures" ...a process that would evolve within a few days into the descent of the Holy Spirit.
They would never be alone. As community, as Church, they would have a common divine soul, the Holy Spirit, the third person of the Blessed Trinity.
Hence the completion of Godís self- revelation to his people ...the ultimate foundation of Christian hope.