The apostles received “the power from on high,” and they began to preach and bear witness to Jesus as the risen 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).
Pentecost is one of the 12 Great Feasts of the Orthodox Church. The Church celibrates the vivifying, the life-giving outpouring of God the Holy Spirit on His people. In the liturgical services of the feast of Pentecost, the coming of the Holy Spirit is celebrated together with the full revelation of the divine Trinity: Father, Son, and Holy Spirit. The fullness of the Godhead is manifested with the Spirit’s coming to man, and the Church hymns celebrate this manifestation as the final act of God’s self-disclosure and self-donation to the world of His creation.