The most important texts of the religion are those of the Avesta, which includes the writings of Zoroaster known as the Gathas, enigmatic poems that define the religion's precepts, and the Yasna, the scripture. The full name by which Zoroaster addressed the deity is: Ahura, The Lord Creator, and Mazda, Supremely Wise. The religious philosophy of Zoroaster divided the early Iranian gods of Proto-Indo-Iranian tradition, but focused on responsibility, and did not create a devil per se. Zoroaster proclaimed that there is only one God, the singularly creative and sustaining force of the Universe, and that human beings are given a right of choice. Because of cause and effect, they are responsible for the consequences of their choices. The contesting force to Ahura Mazda was called Angra Mainyu, or angry spirit. Post-Zoroastrian scripture introduced the concept of Ahriman, the Devil, which was effectively a personification of Angra Mainyu.
Zoroastrianism has no major theological divisions, though it is not uniform; modern-era influences having a significant impact on individual and local beliefs, practices, values and vocabulary, sometimes merging with tradition and in other cases displacing it. In Zoroastrianism, the purpose in life is to "be among those who renew the world...to make the world progress towards perfection". Its basic maxims include:
Humata, Hukhta, Huvarshta, which mean: Good Thoughts, Good Words, Good Deeds.
There is only one path and that is the path of Truth.
Do the right thing because it is the right thing to do, and then all beneficial rewards will come to you also.
The name Zoroaster is a Greek rendering of the name Zarathustra. He is known as Zartosht and Zardosht in Persian and Zaratosht in Gujarati. The Zoroastrian name of the religion is Mazdayasna, which combines Mazda- with the Avestan language word yasna, meaning "worship, devotion". In English, an adherent of the faith is commonly called a Zoroastrian or a Zarathustrian. An older expression still used today is Behdin, meaning "The best Religion | Beh < Middle Persian Weh (good) + Din < Middle Persian dēn < Avestan Daēnā". In Zoroastrian liturgy the term is used as a title for an individual who has been formally inducted into the religion in a Navjote ceremony.
The term Mazdaism (əm/) is a typical 19th century construct, taking Mazda- from the name Ahura Mazda and adding the suffix -ism to suggest a belief system. The March 2001 draft edition of the Oxford English Dictionary also records an alternate form, Mazdeism, perhaps derived from the French Mazdéisme, which first appeared in 1871.