The Baha'i Faith is an Abrahamic religion that originated in Persia (now called Iran) in the 19th century. It is estimated to have 4-8 million adherents spread across the world.
The Baha'i Faith has its origins in Bábism, a religion that emerged in Persia in 1844, when Siyyid ʻAlí-Muhammad proclaimed himself the Mahdi, the prophesized second coming of the 12th Imam in Shia Islam, and adopted the title of Báb, meaning "gate". His claim, was, however, not accepted by most Shia Muslims, and he was branded a heretic, leading to his execution by firing squad for apostasy in 1850 under the orders of the Prime Minister of the Persian Empire. According the most accounts, the Báb survived the first firing squad, and was only killed by the second, and his survival after the first firing squad is considered by Baha'is to be a miracle made by God. The Báb is regarded by Baha'is to be the forerunner of their religion, occupying a role similar to the one John the Baptist does in Christianity.
Mírzá Ḥusayn-ʻAlí Núrí, a Persian nobleman, was one of the followers of the Báb. Following the Báb's arrest in 1848, at the Conference of Badasht, a meeting of the important Bábis of the time, Mírzá Ḥusayn-ʻAlí Núrí adopted the title Baháʼu'lláh, meaning Glory of God. Following an attempted assassination of the King of Persia by two young Bábis following the execution of the Báb, Baháʼu'lláh was arrested since he was one of the most prominent followers of the Báb, and was imprisoned in the dungeon of the king's palace in Tehran. When it became clear that Baháʼu'lláh was not involved in the attempted assassination of the king, he was released from the dungeon but exiled from Persia for life. Baháʼu'lláh thus moved to Baghdad, then part of the Ottoman Empire, and remained in the Ottoman Empire for the rest of his life. While living in Baghdad, Baháʼu'lláh claimed to have received a revelation from God during his imprisonment in Tehran that he was the promised Messiah prophesized by the Báb.
Baha'is believe that there is only one God, and that their religion was revealed in an orderly and progressive way through God's various manifestations, who founded or came as prophets of the world's major religions. Thus, in addition to the Báb and Baháʼu'lláh, Baha'is also honour Abraham, Zoroaster, Krishna, Buddha, Jesus, Muhammad and numerous other figures from the world's other religions as prophets of the Baha'i Faith. The Baha'i Faith stresses the unity and equality of all peoples, explicitly rejecting sexism, racism and nationalism, and calls upon its followers to work towards a unified world order that ensures prosperity for all regardless of race, creed, class or nationality. Baha'is also do not have a clergy, and instead encourage every Baha'i to study the religious scriptures on their own; communal prayers in a Baha'i House of Worship may thus be led by any Baha'i. That said, there is the Universal House of Justice, based in Haifa, Israel, that serves as the central governing body of the religion, with its members elected every five years by members of the various National Spiritual Assemblies throughout the world. The members of the National Spiritual Assemblies are in turn elected by all Baha'is in each country.
The Baha'i place of worship is officially known as a House or Worship, though it is often referred to as a "temple" colloquially.
The Baha'i holy book is known as the Kitáb-i-Aqdas, often shortened to just Aqdas. Baha'is believe that the Aqdas supersedes and succeeds previous revelations by God such as the Bible and the Qur'an.
Since the religion's inception, Baha'is have been heavily persecuted in many Middle Eastern Muslim lands. In particular, the religion is illegal in Iran, its country of origin, where its followers have been branded heretics of Islam, and all Baha'i holy sites in the country were confiscated and demolished following the Islamic Revolution in 1979.
There are eleven holy days in the Baha'i Faith, the first nine of which require practising Baha'is to abstain from work. These are celebrated according to the Baha'i calendar, thus differing in date on the Gregorian calendar every year.
Besides the holy days, another important part of Baha'i tradition is the Nineteen Day Feast, held on the first day of the month in the Baha'i calendar (usually 19 days apart, hence its name). This is when the Baha'i community of each locality gathers to recite prayers together, discuss administrative matters and socialise with each other. The host is expected to serve refreshments to attendees at the social portion of the meeting, but this can be as simple as just serving water if the host is too poor to afford anything more. Non-Baha'is are not permitted to participate in the Nineteen Day Feast. Visiting Baha'is from other localities are permitted to participate, but may not vote on administrative matters.
The Baha'i Faith's holy book, the Kitáb-i-Aqdas, was written in Arabic, though it has also been translated to various other languages of the world. In addition to Arabic, approximately half of the Baha'i writings were also in Persian, the native language of Baháʼu'lláh. The Baha'i Faith explicitly define Arabic and Persian as sacred languages. English is used as the de facto international lingua franca among Baha'is. `Abdu'l-Bahá had praised Esperanto and expressed a desire for an international auxiliary language to be widely adopted, though the language is rarely used in modern-day Baha'i meetings.
Although, the Baha'i pilgrimage as stipulated in the Kitáb-i-Aqdas includes sites in Iran and Iraq, those sites are not accessible to Baha'is as of 2022 because the governments of those countries have outlawed the Baha'i Faith and branded its followers heretics of Islam. Thus, the only Baha'i holy sites that are accessible for Baha'i pilgrimages are the ones in Israel.
Baha'i Houses of Worship are generally divided into three classes, in descending order of hierarchy: continental, national and local. No national Baha'i Houses of Worship have been completed as of 2022, though two are under construction, one in Port Moresby, Papua New Guinea and one in Kinshasa, Democratic Republic of the Congo.
All Baha'i Houses of Worship welcome visitors of all faiths. That said, you are expected to refrain from taking photographs or talking while inside the main auditorium. Although lectures are forbidden, in line with the Baha'i doctrine of honouring the prophets of all religions, religious scriptures of all religions, not just Baha'i ones, may be chanted in the Baha'i House of Worship.