The Hebrew language phrase ruach ha-kodesh (Hebrew: רוח הקודש, “holy spirit” also transliterated ruaḥ ha-qodesh) is a term used in the Hebrew Bible (Tanakh) and Jewish writings to refer to the spirit of YHWH (רוח יהוה). It literally means “spirit of the holiness” or “spirit of the holy place”. The Hebrew terms ruaḥ qodshəka, “thy holy spirit” (רוּחַ קָדְשְׁךָ), and ruaḥ qodshō, “his holy spirit” (רוּחַ קָדְשׁ֑וֹ) also occur (when a possessive suffix is added the definite article is dropped).
The “Holy Spirit” in Judaism generally refers to the divine aspect of prophecy and wisdom. It also refers to the divine force, quality, and influence of the Most High God, over the universe or over his creatures, in given contexts.
For the large majority of Christians, The Holy Spirit (or Holy Ghost, from Old English gast, “spirit”) is the third divine person of The Trinity: The “Triune God” manifested as Father, Son, and Holy Spirit; each aspect itself being God. Two symbols from the New Testament canon are associated with the Holy Spirit in Christian iconography: a winged dove, and tongues of fire. Each depiction of the invisible Heavenly Spirit of God arose from different historical accounts in the Gospel narratives; the first being at the baptism of Jesus in the Jordan River where the Holy Spirit was said to descend in the form of a dove as the voice of God the Father spoke as described in Matthew, Mark, and Luke; the second being from the day of Pentecost, fifty days after Pascha where the descent of the Holy Spirit came upon the Apostles and other followers of Jesus Christ, as tongues of fire as described in the Acts of the Apostles 2:1–31.
For Orthodox Christians, the Theophany and Pentecostal troparion are:
Theophany Troparion (Tone 1): When Thou, O Lord, wast baptized in the Jordan, worship of the Trinity wast made manifest; for the voice of the Father bore witness to Thee, calling Thee His beloved Son. And the Spirit in the form of a dove confirmed the truth of His word. O Christ our God, Who hath appeared and enlightened the world, glory to Thee.
Pentecost, Troparion (Tone 8): Blessed art Thou, Christ our God, Who didst make the fishermen wise by sending down upon them the Holy Spirit, and through them didst draw the world into Thy net. Lover of men, glory to Thee.
Pentecost Kontakion (Tone 8): When the Most High came down and confused the tongues, He divided the nations, but when He distributed the tongues of fire, He called all to unity. And with one accord we glorify the All-Holy Spirit.”