Christians believe in one God who, in a great act of love, created the universe, heaven, earth, and all things therein. Because it was created in love, everything in creation is good and special to God. Christians emphasize God's parental love in particular, teaching that God created humans to be God's children. God wants to share a loving close personal relationship with each of them.
The universe is not only good and moral, but ordered and purposeful. Everything in the cosmos is part of God's divine plan, a plan too great for humans to fully comprehend.
While Christian doctrine traditionally teaches that God is pure spirit, and therefore has no gender, Christians follow Jesus' example and call God Father. The intimacy suggested by the term emphasizes the parental wisdom and love that Christians often ascribe to God. It also describes the relationship that Christians believe Jesus had with God.
Christians teach that Jesus was both human and divine. As a human being he was perfectly obedient to God the Father, and Christians believe they are called to follow his example. As a divine being, he was not another god but a visible incarnation of the one God. He is called the Son of God, the Word of God, or the Image of God as a way of describing his divine origin and nature, and his relationship with God the Father.
Out of the many devotional and honorific titles given to Jesus, the best known is Christ, meaning "anointed," a term that refers to a ceremony in which a king or ruler is consecrated with oil. Christ is the Greek equivalent of the Hebrew title Messiah, or ruler, an indication of the Christian belief that Jesus was sent by God to rule humanity.
Through the miracles he is said to have performed, Jesus revealed God's love, while his teaching revealed God's will. His life and death as a human being were part of God's plan to die voluntarily in order to atone for those who have wronged God.
Christianity teaches that Jesus was raised, or resurrected, on the third day after his death on the cross, and forty days later ascended to heaven, where he lives and reigns alongside God. Christians worship Jesus and pray to him. He is not physically visible now, but is still present wherever his followers gather. Christians expect Jesus to return at some future date to judge humanity and usher in a golden age.
There is a third person of the Godhead, the Holy Spirit. In both Jewish and Christian thought, the Spirit is God's instrument for creating or bestowing life. The Gospel of Matthew says that Mary became pregnant with Jesus through the power of the Holy Spirit; Jesus' own life and ministry were carried out in conjunction with and empowered by the Holy Spirit; and the Gospel of John reports that Jesus assured his followers that although he had to leave, the Spirit of God would come to strengthen them. The Book of Acts describes how, on the day of Pentecost, the Holy Spirit descended on the assembled apostles like powerful wind and flames, and when the Holy Spirit filled them, they were able to speak in languages understood by the pilgrims visiting Jerusalem from far away. Christians view the Holy Spirit as God's active presence in the world.
Although the word Trinity does not appear in the New Testament, it was in use by the early 3rd century. The Nicene Creed states that Jesus is "of one substance" with God the Father. The Holy Spirit "proceeds from the Father," and together with the God the Father and God the Son, "is worshipped and glorified." The idea of the Trinity expresses the Christian belief that the Father, the Son, and the Holy Spirit are three persons in one God. Affirming itself as a monotheistic faith, Christianity has taught that the Trinity is a mystery, beyond the complete comprehension of humans.