Then he led them out as far as Bethany, and lifting up his hands he blessed them. While he blessed them, he parted from them, and was carried up into heaven. And they returned to Jerusalem with great joy, and were continually in the temple blessing God. Luke 24:50-53, RSV.
Here is Luke's other account of the Ascension. Jesus had been with His followers for 40 days since the cross, offering them "many proofs, appearing to them..., and speaking of the kingdom of God" (Acts 1:3, RSV).
And now He was leaving as the disciples stood awestruck as He was caught up to heaven. But the angels assured them that He would return for them in just as public a way as they had seen Him go (verse 11).
Christ's ascension divided their lives into two parts. It signified an ending of their apprenticeship, in which they had been daily taught by the incarnate Jesus. And it also signaled a beginning, in which they would be left to guide and shepherd the church of their risen Lord.
Luke 24:53 tells us that after witnessing the Ascension they "returned to Jerusalem with great joy, and were continually in the temple blessing God" (RSV). That is probably an understatement. My guess is that the apostles and their friends must have fairly skipped all the way back to Jerusalem, shouting to each other as they recounted the events of the past few weeks. They had a great deal to rejoice over. Beyond the shadow of a doubt they knew that they had a friend in heaven. And they couldn't keep their mouths shut.
But they also had other things to attend to. The Ascension took place 40 days after Passover. And Pentecost would occur at day 50. In the interim Jesus had commanded them not to depart from Jerusalem, but to await the promised power of the Holy Spirit.
Acts records that they returned to Jerusalem and "went up to the upper room, where they were staying." Then Luke tells us, after listing the disciples, that "all these with one accord devoted themselves to prayer, together with the women and Mary the mother of Jesus, and with his brothers" (Acts 1:12-14, RSV).
Christianity is more than public rejoicing in the Temple. It is also praying to God in the privacy of our own upper room as we seek Him out for power to witness more effectively to other believers and to the world around us.
The truth of the matter is that in the long run we need quiet time with God if our public work for Him is to have authenticity and power.