Monotheism - the belief that there is a single universal and omniscient God, is the basic underlying concept in numerous religions. But the understanding and worship of that God differs greatly, and has been developed in many world religions, through centuries of study and philosophy. The first monotheistic religion in recorded history is Zoroastrianism, based on the philosophies and teachings of the prophet and founder of the religion - Zoroaster.
Zoroastrianism was founded sometime between the 8th and 6th century B.C., but this religion was not documented in recorded history until the time of the Archaemenid Empire. Zoroastrianism took root and spread throughout the Iranian culture, and was even practiced by royalty in various empires of that period. However, following the Muslim conquest in Persia, Zoroastrianism became a marginalized belief system; some Iranians converted willingly, but others were forced to convert to Islam, which currently is the prevalent religion in that area.
Most scholars believe that Zoroastrianism strongly impacted the beliefs of other monotheistic religions, including Islam, Judaism, and Christianity, although the religion itself actually borrowed some ideas from other religions. The most critical texts related to this religion are found in the Avesta, an accounting that is written in Avestan, which is the language that was spoken throughout the Archaemenid Dynasty. There are other texts used in Zoroastrianism that are not considered to be scriptures inspired by God, but are important supporting texts in the religion. Followers of this religion are referred to as Zoroastrians, or Zarathustrians.
According to the teachings of Zoroaster, there is only a single Creator, who is the Supreme Being that rules over every other creation. This creator, called Ahura Mazda, rules over lesser divine beings created by himself. Zoroaster's teachings were first mentioned in 1643 in Religio Medici by Thomas Browne. According to Zoroastrianism, the good and bad elements in this world are governed by asha, the opposite of chaos, and druj, disorder and falsehood. One inscription in ancient Iran says that druj is the force attempting to disrupt the kingdom of Darius the Great, and dethrone him.
Zoroastrianism beliefs center around actively participating in life through good words, good deeds, and good thoughts, in order to ensure happiness, and keep disorder and chaos away. This participation is the central concept of free will. Zoroastriasts believe that good will eventually triumph over evil, and at that time, the universe will be renovated cosmically, and time will end. The souls of the dead will be reunited with each other when Ahura Mazda returns to life. A savior will bring about the final renovation of the universe, and evil will be forever purged from the world by a tidal wave made of molten metal. People who died as adults will find themselves transformed into being healthy 40-year-old adults. Those who died at a young age will be transformed into being permanently young, about 15 years old. Their new spiritual bodies will never be hungry or thirsty, they will not need weapons because they cannot be injured, and their bodies will be so light that they will not cast a shadow. Everyone in the world will speak one single language, and there will be one single world nation that has no borders. Everyone will share a single goal and purpose - to join together, and exalt the glory of God.
The largest population of Zoroastrianism in the world is located in India. When Persia was invaded by the Islamic sultans, members of the local population who did not want to convert to Islam, began to seek refuge in communities on the western coast of India, and also traveled to other parts of the world. In the last few decades, the United States has become home to the second largest population of the followers of this religion. Some groups are found throughout the world, including central Iran, Pakistan, Canada, England, and Australia. Zoroastrianism communities located in Tehran, Yazd, Kermanshah, and Kerman still speak in the Iranian language of Dari, which is different from Persian. Some Iranians and people of Central Asian countries are beginning to be interested in the ancient heritage of this religion. In 2003, the government of Tajikstan celebrated the 3000th anniversary of the culture of Zoroastrianism, with special events held throughout the world. Thus, Zoroastrianism, the first recorded monotheistic belief system, is enjoying a resurgence in popularity, rather than remaining relegated to the annals of history.