Trinitarianism is a Christian doctrine that defines God as one being in three distinct persons: God the Father, God the Son (Jesus Christ), and God the Holy Spirit. This belief emphasizes that while each person is fully and completely God, they are not three separate gods but rather one unified essence. The concept of the Trinity is foundational in many Christian denominations, including Catholicism, Orthodoxy, and most branches of Protestantism. It seeks to explain the relationship and coexistence of the three persons, highlighting their roles in creation, redemption, and the ongoing work in the world.