Wikipedia
Nara-Narayana (; nara-nārāyaṇa) is a Hindu deity pair. Nara-Narayana is the twin-brother avatar of the God Vishnu on earth, working for the preservation of dharma or righteousness. In the concept of Nara-Narayana, the human soul Nara is the eternal companion of the Divine Narayana.
The Hindu epic Mahabharata identifies the God Krishna (an avatar of Vishnu) with Narayana and Arjuna - the chief hero of the epic - with Nara. The legend of Nara-Narayana is also told in the scripture Bhagavata Purana. Hindus believe that the pair dwells at Badrinath, where their most important temple stands.
The Nara-Narayana pair is frequently worshipped in temples of the Swaminarayan Faith. The followers of the sect believe that their founder Swaminarayan is an incarnation of Narayana.