The word Sabian has been used to refer to a spectrum of believers ranging from the Sabiah Mushrikun (Harranians) at one end to the Sabiah Hunafa (Sebomenoi) at the other. Although these groups may share some common concepts or heritage, it is also possible that they refer to completely different groups of people. Sabi'ism is a spectrum from semi-paganism at one end to perfect enlightenemnt at the other. Thus the Harrian Yazdaeans are sabians at one end of the sabian spectrum but it is not the be all and end all of the story. Sabi'ism is a journey from that end to the enlightened end. It is exactly the same way we have to look at Noahide observance. At one end of the spectrum Trinitarians might have a place according to some authorities, while at the other there is no longer any need to think in such terms.
Ger Toshav, Theosebeia, Sebomenoi and Sabiun
- Sebomenoi/Sebeoi a monotheistic community God Fearers referred to by Greek manuscripts from the Hellenistic-Roman period, modern research indicates that the greek word TheoSeBeia is derived from the hebrew ger ToShaB, and evolved into the word TSaBian 
- Sabians of the Qur'an, or Seboghatullah, a monotheistic community granted religious equality with Jews and Christians, generally assumed to be the same as the Sebomenoi, Ger Toshav.
- Mandaeans a gnostic community that seceded from the Sebomenoi around 60 CE. Mandaean is the term used for the laypeople of the community, and Nasorean is the term used for the priesthood directly descended from the 1st C. BC Notzrim. With the advent of Islam, the only surviving Mandaeans lived in southern Iraq. They were originally protected under Islamic law as Nosaari, but they adopted the name Sabian when Christians assumed exclusive use of the name Nosaari. They continue to live in Lower Babylonia, in the territory of Wasiṭ and Bassora, near Khuzistan. ca. 1st c. CE to the present day, although very few in number.
Harranians same as Yazdâeans
- Sabean of Harran, aka Harranians, a the exonym (ca. 9th and 10th c. CE) for the Yazdâeans gnostic people who have lived in northern Mesopotamia from ancient times. As star-worshippers, Harranians showed a great interest in astronomy, astrology, magic and mathematics. They incorporated astrology and "worship of the heavenly host". From 830 CE until 16th century they adopted the name Sabian to seek protection under Islamic law.
- Yazdânism, or Cult of Angels is a gnostic religious belief of the Kurds
- Sabians of Maimonides The adherents of Yazdânism were referred to as the "Sabians of Harran" (of Carrhae) in Maimonides' Guide for the Perplexed, although may be a composite of Sabaeans, Harranians, Mandaeans and Zoroastrians.
Sabaeans and Sabaians
- Sabaeans were an ancient polytheistic people who worshiped the heavenly host, living in what is now Yemen. (Although they may have had a form of monotheism under the Queen of Sheba). The ancient Sabaean Kingdom lasted from the early 1st millennium (ca. 9th century BC) to the 1st century BC. In the 1st century BC it was conquered by the Himyarites who claimed to be the true Sabaeans, but after the disintegration of the first Himyarite empire of the Kings of Saba' and dhu-Raydan the Middle Sabaean Kingdom reappeared in the early 2nd century. It was finally conquered by the Himyarites around 280 CE. The kingdom of Himyar was the dominant state in Arabia until 525 CE.
- Sabaian refer to the monotheistic followers of Abdullah ibn Saba. A derogatory term for the Shiah, reflecting the claim that Shi'ite Islam was invented by Abdullah ibn Saba, a Yemenite or Persian Muslim-Jew who lived in the time of Caliph Uthman. He may have been a true Quranic Sabian opposing reforms to islam made by the Caliphate. Even so modern Shiah islam shares more in common with Sunni islam than with Seboghatullah.
In the latter ninth century of the Common Era, Arab authors focused upon the origins of the non-gnostic or "Monotheist" Sabians (Sabi'ah Hunafa') from the Gnostic or "Polytheist" Sabians (Sabi'ah Mushrikun) and went into much detail on the Harranian period before the time of Abraham. Most of this knowledge was translated in 904 CE into the book called "The Nabatean Agriculture" which was considered by Maimonides to have been an accurate record of the Gnostic beliefs of the Sabi'ah Mushrikoon (Gnostic Sabians) in the Harranian area. Though Arabic sources go into detail on the origin of Sabiah Hunafa from Sabiah Mushrikun, the Sabiah Hunafa themselves consider their path to be a return to orthodoxy away from the innovations of the Sabiah Mushrikun back to the religion of Noah.
Despite all this substantial and clear documentation about both kinds of Sabians spanning many centuries from sources as diverse as Greek Christian, Arabic Muslim, Arabic and Persian Bahá'í, as well as Jewish sources, the actual nature of the Sabians has remained a matter of some heated debate among western orientalists.
- The confusion of Mandaeans with Sabians. The confusion of western orientalists was due the fact that it was once important for the Mandaean Nasaraeans to seek protection under Islamic law by paying the jizyah tax when Christians began to object to them being classified as Nosaari. By adopting some of Yazdâeans' beliefs, they tried to relate their origins to the Gnostic Yazdâeans who had already made claim to the title "Sabian". Therefore, "Sabian" has been used mistakenly in many literary references for decades and though, the spelling "Sabian" usually refers to one of "people of the book" as mentioned in the Qur'an, it has also been used by the Mandaeans as an appellation adopted to appease local Muslim authorities.
- The confusion of Harranian with Sabians. The variation "Sabean", has been employed in English to distinguish the ancient Harranian origins and Gnostic Yazidi beliefs prior to their rejection of Gnosticism and adoption of Monotheism. In 830 CE the Abbasid caliph al-Ma'mun was passing through Harran on his way to a campaign against Byzantium who forced the Harranians to convert to either one of the 'religions of the book', meaning Judaism, Christianity or Islam. The people of Harran identified themselves with the Sabians in order to fall under the protection of Islam. The Harranian Sabians and the ones mentioned in the Quran have nothing in common. The term Pseudo-Sabian has been used not only by orientalists who take the side of the Mandaeans against the Harranians, but also by orientalists who take the side of the Harranians against the Mandaeans, rendering that term practically useless.
- The confusion of Sabaeans with Sabians began with Marmaduke Pickthall's spelling mistake in his translation of the Qur'an. The word "Sabaeans" comes from a completely different root spelling beginning with the letter "Sin" instead of the letter "Sad". The Sabaeans were in fact the people of ancient Saba in Yemen who have been discredited by scholars as to having any connection to the Sabians of the Qur'an except for their Ansar tribe which practiced Qur'ānic Sabi'ism (Seboghatullah: "submersion in the divine mystery").