Christians believe in God the Father, Jesus Christ as the Son of God, and the Holy Spirit. They believe that the one true God of the Old Testament sent his son Jesus, the messiah, to save the world. The Christian faith centres on beliefs regarding the birth, life, death, resurrection and ascension of Christ and Christ's second coming, the Day of Judgement and salvation of the faithful.
A Christian is “one who believes or professes… to believe in Jesus Christ and the truth as taught by him… one whose life is conformed to the doctrines of Christ.”
A central tenet of many Christian groups is the Trinity. Tthe Trinity consists of the Father, Son and Holy Spirit - three separate persons, all eternal, all present, all powerful, all knowing. They form a single, unified deity. Most Christians believe that Jesus co-existed with God before the foundation of the world.
A few denominations deny the Trinity, including he Church of Jesus Christ of Latter-day Saints (Mormon Church), Jehovah’s Witnesses and the United Pentecostal Church.
Some say if you do not believe in the Trinity, you are not a Christian.
As a tradition, Christianity is more than a system of religious belief. It also has generated a culture, a set of ideas and ways of life, practices, and artifacts that have been handed down from generation to generation since Jesus first became the object of faith. Christianity is thus both a living tradition of faith and the culture that the faith leaves behind. The agent of Christianity is the church, the community of people who make up the body of believers.