Entering the University of Alabama in 1953, Kirk was drawn to the work of a Roman Catholic campus chaplain who opposed segregation. That year, Kirk converted to Melkite Catholicism. He earned a bachelor's degree in social science in 1957, and a few years later moved to New York to work with Dorothy Day at the Catholic Worker House on the Bowery. He earned a master's degree in social thought from Columbia University in 1964 and was ordained as a Melkite priest that year.