Hinduism

It seems that the first people to set foot in the ancient Nepal were Aryans. The Aryans' basic beliefs are recorded in the Vedas, a collection of over one thousand religious hymns that were to form the foundation of the polytheistic religion of Hinduism.
Hinduism has a basic trinity of three gods-Brahma the Creator, Vishnu the Preserver and Shiva the Destroyer. Most Hindus, while revering Brahma, do not usually include his worship in religious ceremonies as his role in the universe is regarded to be essentially completed. Vishnu and Shiva, however, are very important to all the Nepalese Hindus.
Vishnu, whose primary duty is to assure the preservation of the world and all living forms, is believed to have visited the earth ten times as "avatars" or incarnations. He is also believed to have come to the earth as a Varaha, as Prince Rama, as the god Krishna and as Lord Gautam Buddha.
Shiva, the Destroyer, is believed to have three forms-Natraj the god of artistic skill, an anthropomorphic form and the Lingam form, the latter being the most famous Lingam is situated in the north-west of Katmandu. In front of any Shiva temple, one usually sees a statue of Nandi, the divine bull that serves as Shiva's vehicle. In anthropomorphic form, Shiva is depicted with his consort Parbati and usually holds a trident and a small drum. Another popular form of Shiva is terrifying Bhairav, who himself has a number of different forms.
Two of Vishnu's other incarnations- Rama and Krishna-are especially important to the Hindus. Rama and Krishna are the heroes of the classic Hindu epics Ramayana and Mahabharat respectively.
Another widely venerated god is Ganesh, one of the sons of Shiva. Ganesh is revered in Nepal as the god of wisdom and the deity responsible for deciding between success and failure.
In practice, the Nepalese Hindus may choose one particular god as a favorite deity to be worshipped daily, or more likely will give due deference to all the above-mentioned gods and goddesses, along with many other incarnations and deities. Nepal's many Hindu festivals are dedicated to dozens of different deities and are participated by all Hindus, as well as Buddhists.