It commemorates the descent of the Holy Spirit upon the Apostles of Jesus while they were in Jerusalem celebrating the Feast of Weeks, as described in the Acts of the Apostles (Acts 2:1–31).[2] The Catholic Church believes the Holy Spirit descended upon Mary, the mother of Jesus, at the same time, as recorded in the Acts of the Apostles (Acts 1:14).

The term Pentecost comes from Koine Greek: πεντηκοστή, romanized: pentēkostē, lit. 'fiftieth'. One of the meanings of "Pentecost" in the Septuagint, the Koine translation of the Hebrew Bible, refers to the festival of Shavuot, one of the Three Pilgrimage Festivals, which is celebrated on the fiftieth day after Passover according to Deuteronomy 16:10[i] and Exodus 34:22[5] where it is referred to as the "Festival of Weeks" (Koine Greek: ἑορτὴν ἑβδομάδων, romanized: heortēn hebdomádōn).[6][7][8] The Septuagint uses the term Pentēkostē in this context in the Book of Tobit and 2 Maccabees.[9][10][11]

The translators of the Septuagint also used the word in two other senses: to signify the year of Jubilee (Leviticus 25:10)[12][9] an event that occurs every 50th year, and in several passages of chronology as an ordinal number.[ii] The term has also been used in the literature of Hellenistic Judaism by Philo of Alexandria and Josephus to refer to Shavuot.[8]

It commemorates the descent of the Holy Spirit upon the Apostles of Jesus, Mary, and other followers of Christ, while they were in Jerusalem celebrating the Feast of Weeks, as described in the Acts of the Apostles (Acts 2:1–31).[2][3][4] Pentecost marks the "Birthday of the Church".

Since its date depends on the date of Easter, Pentecost is a "moveable feast".

According to legend, King Arthur always gathered all his knights at the round table for a feast and a quest on Pentecost:

“So ever the king had a custom that at the feast of Pentecost in especial, afore other feasts in the year, he would not go that day to meat until he had heard or seen of a great marvel.

The Ten Days of Waiting & the Election of Matthias — The period between Ascension and Pentecost. The Upper Room, the community of prayer, the casting of lots.

Pentecost derives from the Greek term — Pentekoste — fiftieth day. The seven weeks, or fifty days counting inclusively, after the Hebrew Passover. The Christian churches have taken it over and regard it as commemorative of the descent of the Holy Ghost upon the apostles in tongues of fire, as recorded in the New Testament; and they have made it the seventh Sunday after Easter.

THE FORTY DAYS — POST-RESURRECTION APPEARANCES

1. Jesus appears at the Sea of Galilee — the miraculous catch of 153 fish. Breakfast on the shore. The threefold restoration of Peter: "Simon, son of John, do you love me?" Three times. "Feed my sheep." Prophecy of Peter's death. Peter asks about the Beloved Disciple: "What is that to you? You follow me" (John 21)
2. Jesus appears to over 500 at once (1 Corinthians 15:6)
3. Jesus appears to James (1 Corinthians 15:7)
4. The Great Commission — on a mountain in Galilee. "All authority in heaven and on earth has been given to me. Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all that I have commanded you. And behold, I am with you always, to the end of the age" (Matthew 28:16-20)
5. Final teaching — Jesus opens their minds to understand the Scriptures. "Thus it is written, that the Christ should suffer and on the third day rise from the dead, and that repentance for the forgiveness of sins should be proclaimed in his name to all nations, beginning from Jerusalem. You are witnesses of these things" (Luke 24:44-48)
6. The promise of the Holy Spirit — "You will receive power when the Holy Spirit has come upon you, and you will be my witnesses in Jerusalem and in all Judea and Samaria, and to the end of the earth" (Acts 1:8)

THE TEN DAYS OF WAITING

1. The Upper Room — the disciples, the women, Mary the mother of Jesus, and his brothers devote themselves to prayer (Acts 1:12-14)
2. Matthias chosen — to replace Judas among the Twelve. Lots are cast; Matthias is selected (Acts 1:15-26)

PENTECOST — 50 days after Easter

1. The descent of the Holy Spirit — they are all together in one place. A sound like a mighty rushing wind fills the house. Divided tongues as of fire appear and rest on each of them. They are all filled with the Holy Spirit and begin to speak in other tongues (Acts 2:1-4)
2. Peter's sermon — addresses the crowd in Jerusalem. Quotes Joel 2:28-32 and Psalm 16. Proclaims the death, resurrection, and exaltation of Jesus. "God has made him both Lord and Christ, this Jesus whom you crucified" (Acts 2:14-36)
3. "What shall we do?" — "Repent and be baptized, every one of you, in the name of Jesus Christ for the forgiveness of your sins, and you will receive the gift of the Holy Spirit" (Acts 2:37-38)
4. Three thousand baptized — the birth of the Church (Acts 2:41)

John 15:26-27,16:12-15

Jesus said to his disciples: ‘When the Advocate comes, whom I shall send to you from the Father, the Spirit of truth who issues from the Father, he will be my witness. And you too will be witnesses, because you have been with me from the outset.‘I still have many things to say to you but they would be too much for you now. But when the Spirit of truth comes he will lead you to the complete truth, since he will not be speaking as from himself but will say only what he has learnt; and he will tell you of the things to come. He will glorify me, since all he tells you will be taken from what is mine. Everything the Father has is mine; that is why I said: All he tells you will be taken from what is mine.’

- The coming of the Holy Spirit on the disciples, empowering them to preach.

The Great Commission

Jesus gives the Great Commission to His disciples to spread the Gospel.

commemorates the descent of the Holy Spirit upon the Apostles of Jesus while they were in Jerusalem celebrating the Feast of Weeks, as described in the Acts of the Apostles (Acts 2:1–31).[2] The Catholic Church believes the Holy Spirit descended upon Mary, the mother of Jesus, at the same time, as recorded in the Acts of the Apostles (Acts 1:14).

Since its date depends on the date of Easter, Pentecost is a "moveable feast".

The Tongues of Fire at Pentecost

‎"When the day of Pentecost came, they were all together in one place. ‎Suddenly a sound like the blowing of a violent wind came from heaven and filled the whole house where they were sitting. ‎They saw what seemed to be tongues of fire that separated and came to rest on each of them. ‎All of them were filled with the Holy Spirit and began to speak in other tongues as the Spirit enabled them." ‎— ‎Acts 2:1–4 (NIV)

‎ ‎ The same “secret fire” of the alchemist

Helena Blavatsky compared Pentecostal fire to the “descending flame” of divine wisdom that awakens latent faculties in humanity. The tongues of fire upon the head correspond, in occult anatomy, to the crown chakra ignited by the rising Kundalini. ‎ Meister Eckhart wrote that the soul must be “set ablaze by the living fire of God” in order to know divine truth.

Jacob Boehme described fire as the primal quality in which light and love are revealed. For him, Pentecost was the moment when the inner spark of divinity in humanity was fully kindled, making the apostles “flames that bore God’s word into the world.”

‎ ‎The rabbis taught that when the Torah was given at Sinai, it came as “flames of fire, divided, and every people heard it in their own language.” ‎

Cornelius Agrippa, in his Three Books of Occult Philosophy, spoke of the fiery spirit as the source of all magical utterance: words charged with spirit become forces that alter reality.

Rudolf Steiner described Pentecost as the “universalization of the Logos”...a moment when the Word became accessible to all peoples, each tongue carrying the creative fire.

Fire as the medium of divine communication: Agni in the Vedas as messenger between gods and men, Hestia’s eternal flame in Greece, the sacred fire of Zoroastrian temples.