Today marks the day Jesus Christ ascended back to the Father in Heaven. He ascended under His own power, as God the Son. In many dioceses, the celebration of the Ascension is moved to Sunday. Then, the next Sunday is Pentecost, the day the Holy Spirit, sent by God the Son, came upon and gave life to His Church in the Apostles and Mary.
50 Then he led them [out] as far as Bethany, raised his hands, and blessed them. 51 As He blessed them He parted from them and was taken up to Heaven. 52 They did Him homage and then returned to Jerusalem with great joy.
53and they were continually in the temple praising God. (Luke 24)
19 So then the Lord Jesus, after He spoke to them, was taken up into Heaven and took His seat at the right hand of God.
20 But they went forth and preached everywhere, while the Lord worked with them and confirmed the word through accompanying signs.] (Mark 16)
6 When they had gathered together they asked Him, "Lord, are you at this time going to restore the kingdom to Israel?” 7 He answered them, “It is not for you to know the times or seasons that the Father has established by his own authority. 8 But you will receive power when the holy Spirit comes upon you, and you will be my witnesses in Jerusalem, throughout Judea and Samaria, and to the ends of the earth.” 9 When He had said this, as they were looking on, He was lifted up, and a cloud took Him from their sight. 10 While they were looking intently at the sky as He was going, suddenly two men dressed in white garments stood beside them. 11 They said, "Men of Galilee, why are you standing there looking at the sky? This Jesus who has been taken up from you into Heaven will return in the same way as you have seen Him going into Heaven." 12 Then they returned to Jerusalem from the mount called Olivet, which is near Jerusalem, a sabbath day’s journey away.