Ascension Day is the 40th day of Easter, when Jesus Christ ascended into heaven.
The Promise of the Holy Spirit: In the first book, Theophilus, I wrote about all that Jesus did and taught from the beginning until the day when he was taken up to heaven, after giving instructions through the Holy Spirit to the apostles whom he had chosen. After his suffering he presented himself alive to them by many convincing proofs, appearing to them over the course of forty days and speaking about the kingdom of God. While staying with them, he ordered them not to leave Jerusalem, but to wait there for the promise of the Father. ‘This’, he said, ‘is what you have heard from me; for John baptized with water, but you will be baptized with the Holy Spirit not many days from now.’
The Ascension of Jesus: So when they had come together, they asked him, ‘Lord, is this the time when you will restore the kingdom to Israel?’ He replied, ‘It is not for you to know the times or periods that the Father has set by his own authority. But you will receive power when the Holy Spirit has come upon you; and you will be my witnesses in Jerusalem, in all Judea and Samaria, and to the ends of the earth.’ When he had said this, as they were watching, he was lifted up, and a cloud took him out of their sight. While he was going and they were gazing up towards heaven, suddenly two men in white robes stood by them. They said, ‘Men of Galilee, why do you stand looking up towards heaven? This Jesus, who has been taken up from you into heaven, will come in the same way as you saw him go into heaven.’
Acts 1: 1-11
Jesus Appears to His Disciples: Then he said to them, ‘These are my words that I spoke to you while I was still with you – that everything written about me in the law of Moses, the prophets, and the psalms must be fulfilled.’ Then he opened their minds to understand the scriptures, and he said to them, ‘Thus it is written, that the Messiah is to suffer and to rise from the dead on the third day, and that repentance and forgiveness of sins is to be proclaimed in his name to all nations, beginning from Jerusalem. You are witnesses of these things. And see, I am sending upon you what my Father promised; so stay here in the city until you have been clothed with power from on high.’
The Ascension of Jesus: Then he led them out as far as Bethany, and, lifting up his hands, he blessed them. While he was blessing them, he withdrew from them and was carried up into heaven. And they worshipped him, and returned to Jerusalem with great joy; and they were continually in the temple blessing God.