Because it was the coming of the Holy Spirit to the world to dwell in believers and to be our Comforter and Guide. It is the day that the Spirit came to the apostles, and empowered them to begin spreading the Gospel around the world, thus beginning the church of Jesus Christ.
Holy Spirit to come upon them on the day of Pentecost.
I was asking this same question myself, and I have found the answer, and it is fascinating. In Leviticus 23:10-11 and 15-17, The Word of God explains the calculation for what we call Pentecost (the Greek word for 50) as counting 50 days from the Feast of First Fruits, which is the first day after the first Sabbath after Passover. However, contemporary Jewish practice is to celebrate this Pentecost(called the Feast of Weeks in Hebrew, not called Pentecost) 50 days after Passover. In fact, this year, if you count 50 days from the day after the first Sabbath after Passover, you go past June 9, the date published on the Hebrew calendar, and end up on June 16. June 9 is 50 days from Passover. Dr. Thomas McCall, a theologian, wrote an article about this with an explanation about the descrepency, and you can access it at http://www.levitt.com/essays/pentecost.html. I hope this helps you.
Acts ofthe Apostles tells us that Pentecost occurred fifty days after the resurrection of Jesus, but is unclear as to exacly when Stephen was stoned to death. However, it is quite possible that neither event was really historical.The Jews had celebrated a Pentecost since the second century BCE and there are parallels of timing and content between the Jewish Pentecost and the story of the Christian Pentecost, which seems to have been inspired by the Jewish Pentecost. Also, Raymond E. Brown (An Introduction to the New Testament) says that we can never verify the martyrdom or even existence of Stephen. With both events unlikely to have really happened, there is no real answer to this question.
When jesus had died and they were in a room praying as the holy sprit gifted them with the speech of all nationalities
3000 were added to the Church on the day of Pentecost.
No. Pentecost is a Christian-exclusive holiday.
some Christians
In Christianity, the holiday known as Shavuot is called 'Pentecost.' While Jews celebrate God Giving them the Torah on Shavuot, Christians celebrate God Sending them the Holy Spirit on Pentecost.
On Pentecost
Because on Pentecost, we celebrate the Coming Of the Holy Spirit, so on the following Sunday, we celebrate all 3 Divine Persons of the Holy Trinity.
They recognize it, revere it, and acknowledge it's reality, but don't celebrate it in the sense of outwardly expressed traditions.
The Giving of the Torah & the First Fruits.
Many Christians including Catholics celebrate the Easter liturgical season for 50 days from Easter Sunday to Pentecost.
Around 11 of them and they add one for the replace of Judas Iscariot.
Christians celebrate the Trinity all of the time. However, the Sunday after Pentecost is known as 'Trinity Sunday.'
I am a member of a main line arm of Christianity and we do not celebrate the coming of the Holy Spirit on the Day of Pentecost. Perhaps others do?
No. Christmas Day is the day we celebrate Jesus' birthday. Pentecost is the day the Holy Spirit came upon the disciples.