A supermoon raises above the Baha'i Temple in Wilmette, Illinois, Sept. 27, 2015. Reuters

Observers around the world will celebrate World Religion Day Sunday, marking the 67th annual feast dedicated to spiritual unity and interfaith dialogue established by the Baha'i community.

The Baha'i faith is a monotheistic religion originating in 19th-century Persia from followers of Bahá’u’lláh, a spiritual leader born Mirza Hussein Ali Nuri. He taught that humanity needs to "find a unifying vision of the future of society and of the nature and purpose of life" and regarded major figures of other religions such as Jesus, Muhammad and Buddha as messengers or "manifestations" of God. Bahá’u’lláh proclaimed himself the latest of these prophets and sought to link all major religions into one faith.

World Religion Day was first observed in 1947 by Baha'i leader in Portland, Maine by Baha'i scholar Firuz Kazemzadeh and was later officiated in 1950 by the National Spiritual Assembly of Baha'i in the U.S. It is celebrated on the third Sunday of January and seeks to "highlight the essential harmony of the world’s religions, to foster their affinity through interfaith ecumenism, and to promote the idea and ideal of world unity in which the world’s religions can play a potentially significant role," according to scholar Christopher Buck. Since its inception, observation of World Religion Day has been adopted by followers of the faith, including in Latin America, the Middle East and Africa.

Events are often organized by local Baha'i communities, but other faiths have also joined in putting together activities for World Religion Day. Those attending World Religion Day activities are encouraged to pray and discuss the unity of the major theologies. Refreshments and children's activities are also often provided. Religious organizations United Sikhs and Franciscan Sisters have announced support for this year's Word Religion Day. Those observing the holiday internationally include the police department of West Yorkshire, England and Indonesia Muslim preacher Erick Yusuf.