The word "Unitarian" historically refers to the oneness of God as opposed to the Trinity of God, belief in which is referred to as "Trinitarianism".

The word Trinity is not in the Bible, nor Unitarians hold, is the concept. The naming of Father Son and Holy Spirit hardly occurs, except as a echo of a baptismal formula. The doctrine dates from the early Middle Ages, as an effort to reconcile Jewish theology with Greek philosophy, and was adopted as doctrine at the Council of Nicea in 325 AD at the behest of Constantine. The leader of the Trinitarian position was St. Nicholas (later known as Santa Claus), who later actively persecuted Unitarians.

At that time the Unitarian position was called "Arianism" for its leader Arius of Alexandria. He and the idea were declared heretic, and was crushed except for a few remote Germanic tribes.

With the invention of the printing press in the 1450's, and the wide reading of the Bible, people discovered that the Trinity was not there, and Unitarians (often called Arians) sprang up all over Europe like crocus. In most places they were killed. Calvin burned the best known Renaissance Unitarian theologian, the Spaniard Servetus, in Geneva, in 1604. He was burned with a slow fire, taking half an hour to kill him, with his books and writings strapped to him. Earlier he had been burned in effigy by Catholics. (Servetus was also a doctor, and had discovered the pulmonary circulation of the blood.)

Many early Unitarians tended to be scientists or doctors, and serving the royal family sometimes led to acceptance. Krakow (the early capital of Poland), became one of the few places Unitarians were allowed to live without persecution. They formed a convocation in 1565. After the Counter Reformation began to gain strength, and they were less welcome in Krakow, they gathered from all over Europe in a town they settled near Krakow (Rakow), establishing a university and printing press, under the leadership of the Italian theologian Socinus.

Unitarian churches developed in Hungary and Transylvania, and were particularly free in areas controlled by Turkey. Francis David was influential among them, but his thought continued to evolve, out pacing that of some Unitarian thinkers. Sabbatarian Unitarianism developed, observing Jewish food laws and the Sabbath on the seventh day of the week.

With a change in the throne Unitarians in Poland had in 1660 to choose between death, becoming Catholic, or fleeing. Some survivors fled by wagon train to Transylvania, being robbed on their way through Hungary. Some Unitarians in Transylvania later become Jewish by way of Sabatariansim, since Jews were considered infidels rather than heretics, and were not being put to death. Transylvania is the only area with Unitarian church buildings more than 500 years old are still in use by Unitarians. (Structures still exist in Poland, but have been put to other uses.) The Communist government was in the process of destroying those in Transylvania when it fell.

Some Polish Unitarians managed to reach The Netherlands, where the printing press was reestablished, and Unitarian books republished. These were largely in Latin, so could be read by the educated all over Europe. Titles smuggled into England planted the seed of Unitarianism there, and reached New England among the Congregationalists. Unitarianism has always been a movement of books rather than missionaries.

Unitarianism separated from Congregationalism in New England in the early 19th century. You can tell which won the vote in each New England town; in some towns the Congregational building is the older, in others the Unitarian.

The moment of separation in New England is often held to be William Ellery Channing's address at an ordination in 1819. He went on to write on social justice issues, including slavery, labour conditions, and education. Channing abandoned traditional Christian soteriology (salvation through Christ)

Ralph Waldo Emerson, the transcendentalist philosopher was, however, the first American Unitarian divine to influence European thought, the first to reverse the usual direction of the flow of ideas.

Since transcendentalism, Unitarianism has been strongly influenced by humanism, and in more recent years, by the concepts of Eastern religions and earth centred religions.

It was Adolph Harnack in a series of lectures in 1890 who perhaps best expressed the difference between the religion *of* Jesus (an ethical and social justice faith drawing on the fifth century B.C. Jewish prophets), and the religion *about* Jesus (a belief in Christ as sacrificial killed and risen savior, drawing on Paul and medieval theologians).

Unitarianism since Channing can only be considered Christian, if one defines Christianity as being the religion *of* Jesus, not that *about* him. This shift has continued with Emerson and current Unitarian development. Some now consider Unitarianism to be post-Christian.

In the 1930's American Unitarianism almost split between the Theists (those who believe in a personal god), and Humanists (who see human values as paramount). This argument has largely vanished today. In each congregation now you will find both, as well as those who manage to hold both positions simultaneously, as well as other concepts of ultimate reality.

Those who entered Unitarianism in the past generation were primarily "come outers" from more traditional traditions, and were in rebellion against what they regarded as superstitions. Young adults now coming to Unitarianism (often seeking a church school for their children) are more likely to be coming from a secular background and to be seeking spiritual meaning. While humanism remains in first place numerically among Unitarians, those with an "Earth/Nature" centred concept of ultimate reality are now in second place as opposed to the earlier Deists (God made the world but now leaves it alone, the concept of Franklin and Jefferson among others), or Theists.

In the 1960s the Canadian Unitarian Council was formed, and in the United States Unitarians and Universalists combined to form the Unitarian Universalist Association. (Universalists developed in the United States, teaching the universal salvation of humankind.)

These all have in common the idea that values are more important than belief, optimism about the nature of humankind, and valuing the use of reason. It has been said that Unitarians can tolerate anything except intolerance.

Unitarianism is the first non gay denomination to ordain women and gays to ministry, and to perform gay weddings. They are not an historic peace church, but they joined Quakers and Mennonites in opposing the war in Vietnam, and later Iraq. Social action is an important part of the life of the denomination. The first white man killed in the U.S. southern civil rights movement was a Unitarian minister.

Unitarians tend to be more alike in their value system across socioeconomic and geographic lines, but differ in beliefs. Other denominations, from Catholic to Baptist, tend to hold the same beliefs across socioeconomic and geographical lines, but have widely differing values. It is in the commonality of values that we find our community.

Unitarians are a do-it-yourself religion. To be Unitarian you have to work at it. You have to use your mind.

The certainty of dogma, be it Communist, secular humanism, fundamentalist Christian, extreme patriotism, or Islamic fundamentalism, has its appeal. All the answers are given to you. All you have to do is accept, believe, and have faith. Dogma gives you a complete world view, and an understanding of your place in the world.

Unitarians on the other hand are never certain of having the final answers. We have a set of values. We are optimistic about our ability to apply those values to the complexities of our world, and arrive at our own answers concerning right and wrong and appropriate actions. This takes work. While it keeps us small, we have had influence beyond our numbers.

The first ordination of a Canadian Unitarian minister after the organizational separation of the Canadian Unitarian Council (CUC) and the Unitarian Universalist Association (UUA) was held at the First Unitarian Church of Victoria in 2002. Rev. Brian Kiely, who was to give the ordination sermon, was told (partly in jest) he must define Canadian Unitarianism, as Channing had at that ordination sermon in 1819. The simile Brian chose was that Canadian Unitarianism is like a Tim Horton's doughnut, the richness is in the circle of fellowship, not a creedal centre.