Trinitarianism is the group of Christians who believe in the doctrine of Trinity. Today, most Christian denominations and Churches believe this. Churches have different teachings about the trinitarian formula. Some say the Spirit comes only from the Father. Others say the Spirit comes both from the Father and the Son. This is known as filioque. Nontrinitarianism (also called Oneness) is the beliefs systems that reject the Trinity. Many different Nontrinitarian views, such as adoptionism or modalism, existed in early Christianity, leading to the disputes about Christology.