Introduction:
Pentecost, also known as the Day of Pentecost, is a significant event in Christian theology, marking the outpouring of the Holy Spirit upon the apostles and other followers of Jesus Christ. This event is recorded in the New Testament and is celebrated as the birth of the Christian Church. The term "Pentecost" is derived from the Greek word "Pentēkostē," meaning "fiftieth," as it occurs fifty days after the Passover.

Old Testament Background:
Pentecost is rooted in the Jewish Feast of Weeks, or Shavuot, which was a harvest festival celebrated fifty days after Passover. It was one of the three major pilgrimage feasts in Israel, where Jewish males were required to appear before the Lord in Jerusalem. This feast commemorated the giving of the Law at Mount Sinai, which occurred fifty days after the Exodus from Egypt.

New Testament Account:
The Day of Pentecost is described in the Book of Acts, chapter 2. The followers of Jesus were gathered in one place when a sound like a mighty rushing wind filled the house, and tongues of fire appeared and rested on each of them. They were all filled with the Holy Spirit and began to speak in other tongues as the Spirit enabled them. This miraculous event drew a crowd of devout Jews from every nation under heaven, who were bewildered to hear the apostles speaking in their native languages.

Peter, standing with the eleven, addressed the crowd, explaining that this was the fulfillment of the prophecy spoken by the prophet Joel: "In the last days, God says, I will pour out My Spirit on all people" (Acts 2:17). Peter proclaimed the death, resurrection, and exaltation of Jesus Christ, urging the people to repent and be baptized in the name of Jesus for the forgiveness of sins and to receive the gift of the Holy Spirit. About three thousand souls were added to the believers that day.

Theological Significance:
Pentecost is considered the birth of the Church, as it marks the beginning of the apostles' public ministry and the spread of the Gospel. The outpouring of the Holy Spirit signifies the fulfillment of Jesus' promise to send the Comforter, as recorded in John 14:16-17. The event underscores the transition from the Old Covenant, centered on the Law, to the New Covenant, characterized by the indwelling of the Holy Spirit in believers.

The speaking in tongues at Pentecost is seen as a reversal of the confusion of languages at the Tower of Babel (Genesis 11:1-9), symbolizing the unifying power of the Gospel. The Holy Spirit empowers believers for witness and service, as Jesus instructed in Acts 1:8: "But you will receive power when the Holy Spirit comes upon you, and you will be My witnesses in Jerusalem, and in all Judea and Samaria, and to the ends of the earth" .

Liturgical Observance:
Pentecost is celebrated by Christians worldwide, particularly in liturgical traditions, as a major feast day. It is observed on the seventh Sunday after Easter, concluding the Easter season. The liturgical color for Pentecost is red, symbolizing the fire of the Holy Spirit.

Conclusion:
The Day of Pentecost remains a pivotal event in Christian history, emphasizing the transformative power of the Holy Spirit and the universal mission of the Church. It serves as a reminder of the ongoing presence and work of the Holy Spirit in the life of believers and the Church.Acts 2:1
And when the day of Pentecost was fully come, they were all with one accord in one place.
Nave's Topical Index

Acts 20:16
For Paul had determined to sail by Ephesus, because he would not spend the time in Asia: for he hurried, if it were possible for him, to be at Jerusalem the day of Pentecost.
Nave's Topical Index

1 Corinthians 16:8
But I will tarry at Ephesus until Pentecost.
Nave's Topical Index

On Pentecost.
... The Hebdomads of days give birth to Pentecost, a day called holy among them; and
those of years to what they call the Jubilee, which also has a release of land ...
/.../cyril/lectures of s cyril of jerusalem/oration xli on pentecost.htm

The Miracle of Pentecost and the Birthday of the Christian
... and the decayed churches of the East to this day, but in the ... of Cornelius in Caesarea
after his conversion, which may be called a Gentile Pentecost, [272] as ...
/.../schaff/history of the christian church volume i/section 24 the miracle of.htm

The Signs of Pentecost.
... ascertain the significance of the so-called symbols with ... Did the event of Pentecost
then exhaust the prophecy ... Nor could it; the notable day that will exhaust ...
/.../kuyper/the work of the holy spirit/xxvii the signs of pentecost.htm

The Day of Pentecost.
... Thus Pentecost was again rendered illustrious as the commencement of a ... given for
the choice of this day, we may ... Our attention is next called to the subjects of ...
/.../dick/lectures on the acts of the apostles/lecture ii the day of.htm

Pentecost
... it here of Luke: "When the day of Pentecost ... instruction concerning the difference
between our Pentecost and that ... the Gospel; to grace is he called, as Christ ...
//christianbookshelf.org/luther/epistle sermons vol ii/pentecost.htm

Pentecost
... As they called to remembrance the words that Christ had spoken to them before His
death they understood more fully ... "And when the Day of Pentecost was fully ...
//christianbookshelf.org/white/the acts of the apostles/lesson 4 pentecost.htm

Laymen Called to the Field of Missions.
... the strangers from Rome who were present at Jerusalem on the day of Pentecost. ... sentiment,
that lay members of the church in great numbers are called to go ...
/.../dibble/thoughts on missions/chapter v laymen called to.htm

Concerning the Festivals; and How Each Day of Such Festival is to ...
... a week of weeks has passed over after this sacrifice, [which weeks contain forty
and nine days,] on the fiftieth day, which is Pentecost, but is called by the ...
/.../josephus/the antiquities of the jews/chapter 10 concerning the festivals.htm

The Miracle of Tongues.
... difference between the two: the miracle of tongues on the day of Pentecost was
intelligible to ... it was understood only by a few who were called interpreters. ...
/.../kuyper/the work of the holy spirit/xxviii the miracle of tongues.htm

The Apostolate.
... into that body every one that is called must be ... persons of the apostles, took place
on Pentecost, therefore no ... apostolic Word comes to the soul to-day as the ...
/.../kuyper/the work of the holy spirit/xxix the apostolate.htm

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Pentecost: Dictionary and Thesaurus | Clyx.com

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