In mainstream Christianity, Jesus and God are not the same person, but they are the same God in the doctrine of the Trinity: one divine essence existing as three distinct Persons—God the Father, Jesus the Son, and the Holy Spirit—who are coequal, coeternal, yet different in role, with Jesus being fully God and fully human. There is one God, not three separate gods, but God exists as the Father, the Son (Jesus Christ), and the Holy Spirit. The Father sends the Son; the Son comes to Earth (as Jesus); the Holy Spirit empowers believers. However, all three Persons share the exact divine nature, power, and glory, as Jesus is entirely God, so while Jesus is the incarnate Son of God, meaning He is both fully divine and fully human, it is a unique concept within Christianity. While Jesus refers to God as His Father, Jesus is also God, representing God's presence on Earth; yet they are separate Persons within the one Godhead, as evidenced by Jesus' prayer to the Father. Jesus is the Son of God who was crucified and raised from the dead for the salvation of all who trust in Him. Christ is not Jesus's last name; it identifies Him as the Messiah (Christ is the Greek translation of "Messiah"), the fulfillment of Old Testament promises that God would save His people.