The most widely know and the one that is the origin of our liturgical practice is from the Acts of the Apostles. Luke give us a detailed account of this event. It happens near Bethany on the Mount of Olives. It is witnessed by the Apostles and two men in white, a reference perhaps to Elijah and Elisha (2Kings 2) and Elisha's request for a double portion of the Spirit of Elijah. Jesus promises "you will receive power." He promises that he will come back.
The other accounts are so different. John's life of Jesus finishes with the Resurrection account of Thomas' unbelief. The coming of the Spirit and the sending out all happened at this time. "These things are written that you may believe."
Mark's Gospel finishes with the famous verse "these are the signs of believers." "And so the Lord Jesus was taken up into Heaven. There at the right hand of God he took his place, while they, going out, preached everywhere, the Lord working with them and confirming the Word with signs and wonders."
That brings us today to Luke's Gospel.
The Apostles are told to stay in the city until they are clothed with power from on high. They go to the outskirts of Bethany. Jesus blesses them and as he does so he withdrew from them and was carried up to Heaven.
Luke has more to write on another occasion. Scholars say that Luke intended only to write one document, but as it is getting long - remember they wrote on parchment - Luke decided to give a detailed account of the Ascension and Pentecost in another document. We saw this in the Acts of the Apostles.
The end of Jesus' life on earth is told in many ways. It is a story of Jesus returning to the Father, his promise to return and his command to go to the ends of the earth with his message.