When the day of the Jewish Pentecost drew near, the disciples of Christ returned from Galilee to Jerusalem.
On the fortieth day after the resurrection of Jesus Christ, they were all together in one house. Jesus Christ appeared to them and spoke with them saying, "Thus it is written that the Christ should suffer and on the third day rise from the dead, and that repentance and forgiveness of sins should be preached in His name to all nations beginning from Jerusalem. You are witnesses of these things. Go into all the world and preach the Gospel to all creation. He, who believes and is baptized, will be saved, but he, who does not believe, will be condemned. And these signs accompanies those who believe: in My name they will cast out demons; they will speak in new tongues; they will pick up serpents, and if they drink any deadly thing, it will not hurt them; they will lay their hands on the sick, and they will recover."
Then, the Saviour said to the disciples that soon the Holy Spirit would come upon them, and until that time He charged them not to depart from Jerusalem. He said, "I send the promise of My Father upon you; but stay in the city until you are clothed with power from on high; for John baptized with water; but before many days, you shall be baptized with the Holy Spirit."
Conversing with the disciples, the Saviour led them out of the city as far as Bethany to the Mount of Olives. The disciples, overjoyed with the words of the Saviour, surrounded Him and started to ask, "Lord, will You at this time restore the kingdom to Israel?"
The Saviour said to them, "It is not for you to know the times or seasons which the Father has fixed by His own authority. But you shall receive power when the Holy Spirit has come upon you; and you shall be My witnesses in Jerusalem and in all Judea and Samaria and to the end of the earth."
When He had said this, Jesus Christ lifted up His hands and blessed His disciples. While He blessed them, He parted from them, and He was lifted up to Heaven; and soon, a cloud took Him out of their sight.
Thus our Lord and Saviour Jesus Christ ascended in His physical body to Heaven and sat down at the right Hand of God the Father. His human soul and body took on the indivisible glory with His divinity. In His divinity, He always is and will be in Heaven and everywhere.
The disciples worshipped the ascended Lord and for a long time continued to stand and gaze into Heaven after Him. Then, two angels in white robes appeared before them and said, "Men of Galilee, why do you stand looking into Heaven? This Jesus, Who was taken up from you into Heaven, will come to earth in the same way (that is, in the flesh) as you saw Him go into heaven."
After this the disciples of Jesus Christ returned to Jerusalem with great joy and stayed there together awaiting the descent of the Holy Spirit. All of them, together in soul, spent the time in prayer and were continually in the Temple of God praising and thanking God. With them, there were several women and Mary, the Most-holy Mother of the Lord Jesus Christ, with their relatives.
In those days, the apostles prayerfully, by casting lots, chose from among the other disciples of Christ the twelfth apostle, Matthias, to take the place of Judas the betrayer, who perished.
Ascended to Heaven, Jesus Christ according to His own promise invisibly always comes to earth among those who believe in Him, and He will come again to earth in a visible form to judge the living and the dead who will then rise from the dead. After this, the new life will begin, the life of the next age, another, eternal life, which for true believers and pious people will be completely blessed but for disbelievers and sinners will be a time of great torment.
Notes: See the Gospels of Mark 16:15-19 and Luke 24:46-53; Acts of the Apostles 1, 2:4-26.
The Ascension of our Lord Jesus Christ is celebrated by the Holy Orthodox Church as one of the Great Feasts on the fortieth day after Pascha.
Troparion of the Feast
Thou didst ascend into glory, O Christ our God, having gladdened Thy disciples with the promise of the Holy Spirit; and they were assured by the blessing that Thou art the Son of God, the Redeemer of the world.
From The Law of God by Archpriest Seraphim Slobodskoy