God is ascended with jubilee, and the Lord with the sound of a trumpet.
On the feast of the Ascension of our Lord we celebrate the fulfillment of the prophecy of King David, which is used as the Prokimenon of the day. What does it mean for Orthodox Christians? It is not only Jesus Christ Who has ascended; for He has raised human nature itself to the heavens. We too shall rise from the dead and, if we are judged worthy, will rise with our regenerated, spiritual body to heaven, where, as the Blessed Augustine says, “all the people of God shall be made equal to the angels.”
But the thought of this promise reminds us also of our responsibility. The risen Lord is no longer with us in the flesh, but only through His invisible Holy Spirit. The interim between the First and Second Coming of Christ is for us a time of witness and testimony of Him Whom we worship without seeing. The Lord, just before His Ascension, commanded His disciples: Go ye into all the world, and preach the Gospel to every creature (St. Mark 16:15); and He told them, Ye shall be my witnesses … unto the uttermost part of the earth (Acts 1:8).
Christ has been with us for forty days, and we have rightly feasted; we must now, being filled with the Holy Spirit of God, strive to spread His Gospel and be His witnesses before the world. For everything that we do, or fail to do, we shall be judged by Him Who shall return to earth in the same way He ascended to Heaven. With such a sobering thought in mind, how can we not be zealous to make His truth known, so that all may join in the joyous cry of this feast, Be thou exalted, O God, above the heavens, and Thy glory over all the earth (Psalm 107:6 LXX, 108:5 Hebrew text).
From The Heavenly Realm, St. Herman of Alaska Brotherhood, 1983