Historic Unitarianism believed in the oneness of God as opposed to traditional Christian belief in the Trinity (Father, Son, and Holy Spirit). Historic Unitarians believed in the moral authority, but not the deity, of Jesus. Unitarians are characterized by some as being identified through history as free thinkers and dissenters, evolving their beliefs in the direction of rationalism and humanism.
Throughout the world, many Unitarian congregations and associations belong to the International Council of Unitarians and Universalists. Today, most Unitarian Universalists do not consider themselves Christians, even if they share some beliefs quite similar to those of mainstream Christians.