The oldest attested use of the term is in Yasna 39.3, which is part of the Yasna Haptanghaiti and in which the two elements of the name occur in reverse order, that is, as Spenta Amesha. Like all other verses of the Yasna Haptanghaiti, Yasna 39.3 is also in Gathic Avestan and is approximately as old as the hymns attributed to Zoroaster himself.
This meaning is particularly evident in the 9th-14th century texts of Zoroastrian tradition, but there are also instances in the Avesta proper where it is used this way. In Yasna 1.2 for instance, the yazata Atar is declared to be "the most active of the Amesha Spentas." Even in present-day Zoroastrianism, the term is frequently used to refer to the thirty-three divinities that have either a day-name dedication in the Zoroastrian calendar or that have a Yasht dedicated to them (or both).
This general, non-specific, meaning of the term Amesha Spenta also has an equivalent in the Vedic Sanskrit Vishve Amrtas, which is the collective term for all supernatural beings (lit: 'all immortals').
As enumerated in Yasna 47.1 of the Gathas, the six 'divine sparks' are:
In later tradition, the attributes (like vahishta "best") in four of the names are integral to the names themselves. In the Gathas however, the poet uses the terms asha et al as qualities that each of the Amesha Spenta represents and which mortals should strive to possess. Thus, the doctrine of the great six is that through good thoughts, words and deeds, each individual should endeavor to assimilate the qualities of the Amesha Spenta into him-/herself.
While Vohu Manah, Asha Vahishta and Kshathra Vairya are consistently of neuter gender in Avestan grammar, in tradition they are considered masculine. Armaiti, Haurvatat and Ameretat are invariably feminine.
In the Gathas, the six Amesha Spentas represent the good feelings (Happiness) which we should strive to obtain. Each of the six is assigned an antithetical counterpart: In the Gathas, in addition to aša/arta- opposed to the druj-, vohu-mahah is opposed to aka-manah-, kshathra- to dushae-kshathra-, and armaiti- to taraemaiti-. Although not evident in the Gathas, in the Younger Avesta haurvatat- "wholeness" appears is opposition to tarshna- "thirst" and ameretat- "life" is opposed to shud- "hunger." These latter two assignments reflect Haurvatat's identification with water and Ameretat's identification with plants.
In the Gathas, aša/arta is the most evident of the six, and also the most commonly associated with Wisdom (Mazda). In the 238 verses of these hymns, aša-/arta- appears 157 times. Of the other concepts, only vohumanah- appears nearly as often (136 occurrences). In comparison, the remaining four of the great sextet appear only 121 times altogether: kshathra-: 56 times; armaiti-: 40; ameretat-: 14; haurvatat-: 11 times.
In the context of Zoroastrian view of creation, the group of the Amesha Spenta is extended to include Ahura Mazda, together with (or represented by) Spenta Mainyu. However, in most scholastic texts, an unqualified referral to the "Amesha Spenta" is usually understood to include only great six. In Yasna 44.7, 31.3, and 51.7, Ahura Mazda's Spenta Mainyu is the instrument or "active principle" of the act of creation. It is also through this 'Bounteous Force', 'Creative Emanation' or 'Holy Spirit' that Ahura Mazda is immanent in humankind (Yasna 33.6), and how the Creator interacts with the world (Yasna 43.6).
The doctrine also has a physical dimension, in that each of the heptad is linked to one of the seven creations, which in ancient philosophy were the foundation of the universe. These physical associations are only alluded to in the Gathas, and then so subtly that they are usually lost in translation.
A systematic association is only present in later middle Persian texts, where each of the seven is listed with its "special domain":
In the Gathas, Kshathra [Vairya] does not have an association with a specific creation, and it is only in later texts that this Amesha Spenta is considered the guardian of metals. This anomaly is explained in modern scholarship by the fact that, in Stone Age cosmogony, the sky was considered to be the first of the creations (and thought to be of stone), but metal has no place among the creations (the bronze and Iron Ages were yet to come). This is also reflected in Zoroaster's revelation, where the sky is "of the hardest stone" (Yasna 30.5). Later, with the event of bronze and then iron tools, this sky evolved to being of crystal, which was seen as both of stone and of metal (Yasht 13.2). In due course, Kshathra's association with a stony firmament was eclipsed by the association with a metallic sky, and thence to metals in general.
The relationship between Ahura Mazda and the Amesha Spenta is an altogether subtle one. In Yasna 31.11 of the Gathas, Ahura Mazda is said to have created the universe with his "thought". In other passages such as Yasna 45.4, Ahura Mazda is described as the metaphorical "father" of the individual Amesha Spenta, which, even though figurative, suggests a familial closeness. In particular, the relationship between Ahura Mazda and Spenta Mainyu is multifaceted and complex, and "as hard to define as that of Yahweh and the Holy Spirit in Judaism and Christianity."
A veneration for the 'divine sparks' through the living world is still present in modern Zoroastrian tradition and is evident in every religious ceremony where each of the Amesha Spenta is visibly represented by objects of which they are the guardians. In addition, the first seven days of the month of the Zoroastrian calendar are dedicated to the great heptad and to creation, so acknowledging the preeminence of the Amesha Spenta, and so ensuring the inculcation of their doctrine.
Spiritual and material dualism in the same entity "accounts for the difficulty which some aspects of the doctrine have presented for Western scholars." The reverence of the Amesha Spenta has been frequently attacked as de-facto polytheism, not only in modern times, but in the Sassanid era as well. While the "worship of the elements" was a repeated accusation during the 4th and 5th centuries, Christian missionaries (such as John Wilson) in 19th century India specifically targeted the immanence of the Amesha Spenta as indicative of (in their view) Zoroastrian polytheistic tradition. A frequent target for criticism was the Zoroastrian credo in which the adherent declares: "I profess to be a worshiper of Mazda, follower of the teachings of Zoroaster, ... one who praises and reveres the Amesha Spenta" (the Fravaraneh, Yasna 12.1). Whether one who reveres the Amesha Spenta is, by that definition, a polytheist is subject to interpretation. Zoroastrians themselves note that ethereal spirit and physical manifestation are not separatable, and that a reverence of any of Ahura Mazda's creations is ultimately a worship of the Creator.
In the second half of the 19th century, Martin Haug proposed that Zoroaster himself had viewed the Amesha Spenta as philosophical abstractions, and that a personification of the heptad was really a latter-period corruption. The Parsis of Bombay gratefully accepted Haug's premise as a defence against the Christian missionaries, and subsequently disseminated the idea as a Parsi interpretation, so corroborating Haug's theory. The "continuing monotheism" principle eventually became so popular that it is now almost universally accepted as doctrine.