Angus MacLean and Sophia Lyon Fahs, two of the most important religious educators for the Unitarian, Universalist, and Unitarian Universalist movements, left indelible—and foundational—marks on the landscape of liberal religious education.

Angus MacLean was Professor of Religious Education and Psychology, and later Dean, at Canton Theological School of St. Lawrence University in Canton, New York. Born in 1892 to a Scottish Presbyterian family in Nova Scotia, MacLean was educated in Canada and the U.S., becoming an instructor at Columbia University's Teachers College in the mid-1920s. There he was introduced to, and greatly influenced by, the philosophy and writings of the progressive educator John Dewey. After his move to Canton in 1928, MacLean formally left behind the religious tradition of his younger years. In his book The New Era in Religious Education (1934), he charted a new direction, proposing a child-centered, experience-centered approach to church school philosophy. He was ordained to the Universalist ministry in 1945, and in 1946, was the first chair of a new committee created to oversee the Department of Education in the Universalist Church of America (UCA).

While at Canton, MacLean increased the offerings for those training for a vocation in parish ministry and in religious education, adding courses in philosophy of education, child growth and development theory, curriculum development, and the use of the creative arts in religious education. MacLean believed religious education must be relevant to the child, the church, and the problems of the world; above all, he proclaimed "the method is the message," meaning that how children are taught is likely more important than what they are taught. In a 1962 UUA pamphlet, he said, "Such values as we are concerned with cannot be communicated except as they are set in operation, given life, in the human relations in which teachers and taught are involved." When he died in 1969, he was eulogized as a "champion of the spiritual rights of children."

Sophia Lyon Fahs, MacLean's senior by 16 years, was also born into a Presbyterian family, but in Hangchow, China in 1876. She, too, was greatly influenced at Columbia University Teachers College by the work of John Dewey. After earning a degree in divinity from Union Theological School, Fahs began teaching at Union as well as serving on the church school staff at Riverside Church in New York. While at Union, Fahs had learned about the Beacon Series of religious education curricula published by the American Unitarian Association (AUA), and, through those books, was introduced to Unitarianism. In 1930, Fahs was invited to the religious education conference at Star Island, New Hampshire, marking her formal, and henceforth active, involvement with Unitarianism. In 1937, at the age of 60, she was invited by the AUA to become Editor of Curricula, a post she held for 17 years. She was ordained to the Unitarian ministry in 1959.

Along with Ernest Kuebler, Fahs was responsible for the New Beacon Series, a visionary, expansive, and ambitious curriculum published by the AUA from the 1930s through the mid-1960s. The series brought together, for the first time, understandings from progressive education, liberal theology, and biblical criticism, and lifted up a child's natural experiences and their questions as central to the religious life of children and youth. Fahs summed up her optimistic and grand philosophy thus: "We need to learn how to help children to think about ordinary things until insights and feelings are found which have a religious quality." In her ground-breaking book, Today's Children and Yesterday's Heritage, she wrote, "Beliefs... should be the products of maturing emotional experiences, meditation, and critical thought, and not assumptions with which to begin."

In more than 30 published works, Fahs explored themes such as the relevance of religion in the modern world, the integration of religion and science, and the universality of religious experiences. In Beginnings, she demonstrated through creation stories and scientific explanations that the same questions of meaning and mystery are asked by all peoples at all times. The Martin and Judy series included stories for every age level and emphasized that religious values exist in the home and community as well as at church. Stories from the Bible included insights from contemporary scholarship and biblical criticism. Consultants for the curricula included authorities from the fields of child development, education, and psychology. Curricula included books children could read themselves, activities drawn from the arts and the natural world, and guides for teachers and parents.

MacLean and Fahs shared much. They both came from another religious tradition, finding Universalism and Unitarianism as adults. Both were influenced by the work of John Dewey and applied his theories of public education to religious education. Both were loved by their students for their creative spirits and their clear devotion to their work.

Institutional conditions laid the path for both MacLean's and Fahs' work, as both the AUA and the UCA came to to better understand the role of religious education in revitalizing and renewing churches. In 1936, the AUA Commission of Appraisal Report, Unitarians Face a New Age, called for more emphasis on religious education for the benefit of all Unitarians. At the same time, the UCA recognized that growth in their churches was closely tied to the activity of their General Sunday School Association.

The two denominations found common ground through sharing materials. By the mid 1940s, most Universalist churches were using the AUA's New Beacon Series. The work of Fahs and MacLean strongly influenced the religious development of the generation who would come to adulthood in the new Unitarian Universalist Association.