As compared to Trinitarians, who believed in a triune God – a single God in three persons (i.e. Father, Son, Holy Spirit) or trinity – the key Unitarian belief was in the oneness - or unity - of God. To Unitarians, the life and teachings of Jesus Christ constituted the exemplar model for living one's life, but that Jesus himself was neither God nor some portion of a pluralistic God. Unitarians believed that Jesus was - at most – a great religious teacher or prophet, an example from which we can learn and reach our potential.
Unitarianism was opposed to certain Trinitarian doctrines, such as predestination, eternal damnation, and vicarious sacrifice, which they believed malign God's character or veiled the true nature and mission of Jesus Christ. Human nature being neither inherently corrupt nor depraved, was capable of both good and evil, which Unitarians believe God intended for us. They believe God left humans free to exercise their will in the world, that religion helps us do so in a responsible, constructive and ethical manner, and reason, rational thought, science, and philosophy coexist compatibly with faith in God. Unitarians accept that the authors of Biblical scripture were inspired by God, but were nonetheless human and therefore subject to human error, and that no religion can claim an absolute monopoly on holiness or theological truth.
Worship within the Unitarian tradition accommodates many understandings of God, while its religious services are much like a celebration of life. Unitarian congregations may devise their own forms of worship, though they commonly light their chalice as a symbol of faith, present a story for all ages, and may present sermons, prayers, hymns, and songs. Sometimes, attendees share publicly their joys or concerns.