In the new covenant of the Messiah, the passover event takes on its new meaning as the celebration of Christ’s death and resurrection, the “exodus” of men from this sinful world to the Kingdom of God. And in the New Testament as well, the pentecostal feast is fulfilled and made new by the coming of the “new law,” the descent of the Holy Spirit upon the disciples of Christ.
When the day of Pentecost had come they were all together in one place. And suddenly a sound came from heaven like the rush of a mighty wind, and it filled all the house where they were sitting. And there appeared to them tongues as of fire, distributed as resting upon each one of them. And they were all filled with the Holy Spirit . . . (Acts 2.1–4).The Holy Spirit that Christ had promised to his disciples came on the day of Pentecost (Jn 14.26, 15.26; Lk 24.49; Acts 1.5). The apostles received “the power from on high,” and they began to preach and bear witness to Jesus as the risen Christ, the King and the Lord. This moment has traditionally been called the birthday of the Church.
On Pentecost we have the final fulfillment of the mission of Jesus Christ and the first beginning of the messianic age of the Kingdom of God mystically present in this world in the Church of the Messiah. For this reason the fiftieth day stands as the beginning of the era which is beyond the limitations of this world, fifty being that number which stands for eternal and heavenly fulfillment in Jewish and Christian mystical piety: seven times seven, plus one.
While those on whom the Spirit had descended were speaking in many languages, the Apostle Peter stood up with the eleven and proclaimed to the crowd that this event was the fulfillment of the prophecy ("I will pour out my spirit").
In Acts 2:17, it reads: "'And in the last days,' God says, 'I will pour out my spirit upon every sort of flesh, and your sons and your daughters will prophesy and your young men will see visions and your old men will dream dreams." He also mentions (2:15) that it was the third hour of the day (about 9:00 am). Acts 2:41 then reports: "Then they that gladly received his word were baptized: and the same day there were added unto them about three thousand souls."
Peter stated that this event was the beginning of a continual outpouring that would be available to all believers from that point on, Jews and Gentiles alike.
Pentecost was the beginning of the last days of God pouring out his spirit which have been ongoing since. In the end times, there will be an increase just as it was in Apostolic times.