Pentecost is the celebration of the Holy Spirit descending on the apostles after the Ascension of Jesus.
Pentecost is celebrated on the seventh Sunday after Easter.
The Holy Spirit
The Holy Spirit, is the third person of the Trinity. The Triune God manifested as God the Father, God the Son, and God the Holy Spirit; each entity itself being God.
The Holy Spirit descended on Jesus like a dove during his baptism, and in his Farewell Discourse after the Last Supper, Jesus promised to send the Holy Spirit to his disciples after his departure.
The Holy Spirit is referred to as "the Lord, the Giver of Life" in the Nicene Creed.
The Dove
The Holy Spirit is often depicted as a dove, based on the account of the Holy Spirit descending like a dove on Jesus at his baptism.
The book of Acts describes the Holy Spirit descending on the apostles at Pentecost in the form of a wind and tongues of fire resting over the apostles' heads. Based on the imagery in that account, the Holy Spirit is sometimes symbolized by a flame.
Here at The Grotto, the Holy Spirit is represented as a dove both in paintings and sculpture.
Prayer
Holy Spirit pour down upon us your gifts of wisdom, understanding, courage, grace and peace.
May your gifts unify and strengthen each and every heart of those who are gathered in Christ Jesus.