Origen of Alexandria (c. 185-250 CE) was an early Christian theologian who articulated ideas of universal salvation in ways that led his critics to charge him with heresy centuries after his death. From all accounts, Origen was a brilliant, gifted, and prolific scholar who studied science, philosophy, and theology and created the first systematic theology of Christianity, De Principiis, or On First Principles. This great work survived in its original Greek only in fragments; in the year 543, the emperor Justinian issued an edict condemning Origen's writings, and ordered them destroyed.
Origen's basic premises were:
First, That the souls of humans had existed in a previous state, and that their imprisonment in material bodies was a punishment for sins which they had committed;
Second, That the human soul of Christ had also previously existed, and been united to the Divine nature before the incarnation of the Son of God which is related in the Gospels;
Third, That our material bodies shall be transformed into absolutely ethereal ones at the resurrection; and
Fourth, That all humans, and even devils, shall be finally restored through the mediation of Christ.
While all these ideas were important in the development of Christian theology, of particular interest to Unitarian Universalists is Origen's "major heresy," that because Christ redeemed all humans, all would be saved in eternity. Origen did not believe in eternal suffering, and theorized that souls are re-born, over and again, to experience the educative powers of God until they finally and eventually achieve salvation.
Origen died c. 250 CE, from wounds he received from torture for expressing and spreading his ideas in nearly 2,000 separate written works.