1. Hinduism

Dating back to the 15th - 5th century BCE, Hinduism is not a unified religion with a distinct belief system, but rather comprises a variety of traditions adhered to by Hindus who have identified as such for centuries in opposition to other religions. The central belief shared by the religion's diverse followers is faith in the Vedas, the oldest scriptures compiled on the Indian subcontinent. As such, Hinduism is recognized as the world's oldest religion. Over time, it has evolved into a flexible and diverse tradition with the ability to integrate potentially divisive changes. Today, there are nearly one billion Hindus worldwide. To learn more about this ancient faith, visit Kerala and Nepal, where Hinduism is the predominant religion.

2. Zoroastrianism

.Zoroastrianism,an ancient Indo-Iranian religion also known as Mazdayasna, traces its origins to the 2nd millennium BCE and underwent significant changes following the teachings of the prophet Zoroaster (Zarathustra), believed to have lived between the 10th and 6th centuries BCE. With a profound influence on the development of the Abrahamic tradition, it served as the official religion of various Persian empires until the 7th century CE when it was displaced by Islam. Nevertheless, it continues to be practiced by an estimated 200,000 people in Iran, India, and Iraq. Additionally, three related Kurdish religious variants known as Yazdânism, which combine elements of Islam and a precursor to Zoroastrianism, have emerged, featuring a belief in the existence of seven angels who protect the world from evil and a doctrine of reincarnation. These creeds are likely as old, if not older, than Zoroastrianism.

3.Judaism

Judaism originated in the Levant around the 9th century BCE and is the oldest monotheistic religion still in existence. Christianity and Islam are its two successor faiths and are the world's most popular religions. Jainism is a religion based on the teachings of omniscient preachers of the Jain path, and is said to number six to seven million followers worldwide. Confucianism, a humanistic and least spiritual creed on this list, has a supernatural worldview influenced by Chinese folk tradition and is one of the leading influences on modern Chinese folk religion, with six million strict Confucianists. Buddhism, founded by Siddhartha Gautama in the northernmost regions of the Indian subcontinent, continues to be followed by at least 400 million people today. Taoism is a religion evolved from a strand of traditional Chinese folk religion, with 170 million Chinese claiming some affiliation, and 12 million strictly following it. Shintoism, a direct descendant of the animistic folk religion of the Yayoi, is followed by the vast majority of Japan's population.

4.Confucianism

Confucianism,which dates back to the 6th to 5th century BCE, can be traced to Confucius, a Chinese politician, teacher, and philosopher who claimed to be part of an earlier scholarly tradition. Although it is the most humanistic and least spiritual among the listed religions, Confucianism includes a supernatural worldview influenced by Chinese folk tradition, which incorporates Heaven, the Lord on High, and divination. Despite going through various periods of popularity and unpopularity in China, Confucianism remains one of the primary influences on modern Chinese folk religion, with about six million strict Confucianists.

5.Buddhism

Buddhism (6th – 5th century BCE) In contrast to other religions on this list, the history of Buddhism is relatively clear. It can be traced back to one individual, Siddhartha Gautama, also known as Buddha. He established his own monastic order in the northernmost regions of the Indian subcontinent around the 6th to 5th centuries BCE. Although his teachings were recorded after his death, they are still followed by approximately 400 million people today, albeit with some significant differencees.

6.Taoism 

Taoism (6th – 4th century BCE) is believed to have originated from a work called the Tao Te Ching, attributed to Laozi, a mythical figure from around the same time as Confucius. The religion was influenced by traditional Chinese folk religion and references ancient figures and teachings, such as the Yellow Emperor and the I Ching. Today, approximately 170 million Chinese people claim some connection to Taoism, with 12 million practicing it strictly.

7. Shintoism

Shintoism, which originated from the animistic folk religion of the Yayoi culture in the 3rd century BCE, was not formally organized until 712 CE when it was influenced by Confucianism, Buddhism, and Taoism. Today, it is a unified belief system that combines ancient Japanese mythology with strong Buddhist influences and is widely practiced by the population of Japan, although only a small percentage identify as part of an organized religion.

8.Jainism

Jainism (8th - 2nd century BCE) Although once a dominant religion in the Indian subcontinent, Jainism's origins are somewhat obscure. Its adherents follow the tirthankaras, who are all-knowing preachers of the Jain path, and who are known for their asceticism and self-discipline. While the last two tirthankaras, Parshvanatha (8th century BCE) and Mahavira (599-527 BCE), are historical figures, archaeological evidence proving the existence of Jainism only dates back to the second century BCE. Today, Jains are estimated to number between six and seven million globally.