Holy Spirit in Christianity

For the majority of Christian denominations, the Holy Spirit, or Holy Ghost, is believed to be the third person of the Trinity, a Triune God manifested as God the Father, God the Son, and God the Holy Spirit, each Person being God. Nontrinitarian Christians, who reject the doctrine of the Trinity, differ significantly from mainstream Christianity in their beliefs about the Holy Spirit. In Christian theology, pneumatology is the study of the Holy Spirit. Due to Christianity's historical relationship with Judaism, theologians often identify the Holy Spirit with the concept of the Ruach Hakodesh in Jewish scripture, on the theory that Jesus was expanding upon these Jewish concepts. Similar names, and ideas, include the Ruach Elohim (Spirit of God), Ruach YHWH (Spirit of Yahweh), and the Ruach Hakodesh (Holy Spirit). In the New Testament it is identified with the Spirit of Christ, the Spirit of Truth, the Paraclete and the Holy Spirit. The New Testament details a close relationship between the Holy Spirit and Jesus during his earthly life and ministry. The Gospels of Matthew and Luke and the Nicene Creed state that Jesus was "conceived by the Holy Spirit, born of the Virgin Mary". 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, which summarises several key beliefs held by many Christian denominations. The participation of the Holy Spirit in the tripartite nature of conversion is apparent in Jesus' final post-resurrection instruction to his disciples at the end of the Gospel of Matthew, "Make disciples of all the nations, baptizing them into the name of the Father and of the Son and of the Holy Spirit." Since the first century, Christians have also called upon God with the trinitarian formula "Father, Son and Holy Spirit" in prayer, absolution and benediction.