Ekasarana Dharma (Assamese ?; literally: 'Shelter-in-One religion') is a panentheistic form of Hinduism founded and propagated by Srimanta Sankardeva in the 15th century. Most of the adherents of this religion today live in the Indian state of Assam. As part of the greater Bhakti movement in other parts of India, it rejects vedic and other esoteric rites of worship, and instead replaces them by a simplified form that requires just uttering the name (naam) of God.
The simple and accessible religion attracted already Hinduized as well as non-Hindu tribal populations into its egalitarian folds. The new converts were accepted via a system of individual initiation and were given a path to social improvement. Institutions like sattra (monasteries) and village Namghar (prayer houses), had profound influence in the evolution of social makeup of Assam's society. The artistic oeuvres lead to engendering of new forms of literature, music (Borgeets or songs celestials), theatre (Ankia Naat) and dance (Sattriya dance).
The central religious text of this religion is Bhagavat of Sankardeva, which was transcreated from the Sanskrit Bhagavata Purana by Srimanta Sankardeva and other religious preceptors. This book is supplemented by the two books of hymns: Kirtan Ghoxa by Sankardeva and Naam Ghoxa by Madhabdev. These books are written in the Assamese language.
The religion is also called Mahapuruxiya because it is based on the worship of the Mahapurux or Mahapurush (Sanskrit: Maha: Supreme and purush: Being), an epithet of Lord Vishnu in the Bhagavata and its adherents are often called Mahapuruxia, Sankari, Saraniya etc. In course of time, the epithet 'Mahapurux' came to be (secondarily) applied also to Sankardeva and Madhabdev, the principal preceptors. Non-adherence to the Hindu varnasrama system and egalitarianism marked its character.
A strictly monotheistic religion, the only form of worship prescribed by this religion is uttering the name of God ("Sravana-Kirttana"), who is worshiped in the form of Krishna or Hari. Thus it is also called ek sarana Hari naam dharma. Though a part of the wider Bhakti movement, it does not worship Radha with Krishna which is common in other bhakti movements. It is characterised by the dasya form of worship. Historically, it has been against caste system, and especially against animal sacrifices common in sakta forms of Hinduism. Noted for its egalitarianism, it posed a serious challenge to Brahminical Hinduism, and converted into its fold people of all castes, ethnicity and religion (including Islam). Idol worship is a taboo.
The preceptors as well as later leaders of the Ekasarana religion focused mainly on the religious practice of bhakti and kept away from systematically expounding philosophical positions. Nevertheless references found scattered in the voluminous works of Sankardeva and Madhavdeva indicate that their theosophical positions are rooted in the Bhagavata Purana with a strong Advaita influence via its commentary Bhavartha-dipika by Sridhar Swami. Nevertheless, Sankardeva's interpretation of these texts were seen at once to be "original and new". Scholars hold that these texts are not followed in-toto and deviations are often seen in the writings especially when the original philosophical contents came into conflict with the primary focus of bhakti as enunciated in the Ekasarana-dharma.
Though it acknowledges the impersonal (nirguna) god, it identifies the personal (saguna) one as worshipful which it calls Narayana. The sole aspect that distinguishes the personal from the impersonal one is the act of creation, by which Narayana created everything. Unlike in Gaudiya Vaishnavism it claims no distinction between Brahman, Paramatman and Bhagavat, which are considered in Ekasarana as just different appellations applied to the same supreme reality.
Narayana as the personal and worshipful god is considered to be a loving and lovable god, who possesses auspicious attributes that attract devotees. He is non-dual, omnipotent and omniscient; creator, sustainer, and destroyer of all. He also possesses moral qualities like karunamaya (compassionate), dinabandhu (friend of the lowly), bhakta-vatsala (beloved of devotees) and patit-pavana (redeemer of sinners) that make him attractive to devotees. Though it does not deny the existence of other gods, it asserts that Narayana alone is worshipful and the others are strictly excluded.
Following the Bhagavata Purana, the object of devotion in Ekasarana is Krishna, who is the supreme entity himself. who is suddha (pure), satya (true). All other deities are subservient to Him. Brahman, Vishnu and Krishna are fundamentally one. Krishna is alone the supreme worshipful in the system. Sankaradeva's Krishna is N?r?yana, the Supreme Reality or Parama Brahma and not merely an avatara of Visnu. Krishna is God Himself. It considers Narayana (Krishna) as both the cause as well as the effect of this creation, and asserts Narayana alone is the sole reality. From the philosophical angle, He is the Supreme Spirit (Param-Brahma). As the controller of the senses, the Yogis call him Paramatma. When connected with this world, He assumes the name of Bhagavanta. Moreover, some of the characteristics usually reserved for the impersonal God in other philosophies are attributed to Narayana with reinterpretations.
The embodied self, called jiva or jivatma is identical to Narayana. It is shrouded by maya and thus suffers from misery, When the ego (ahamkara) is destroyed, the jiva can perceive himself as Brahma. The jiva attains mukti (liberation) when the jiva is restored to its natural state (maya is removed). Though other Vaishnavites (Ramanuja, Nimbarka, Vallabha, Caitanya) recognise only videhamukti (mukti after death), the Ekasarana preceptors have recognised, in addition, jivanmukti (mukti during lifetime). Among the five different kinds of videhamukti, the Ekasarana rejects the Sayujya form of mukti, where the complete absorption in God deprives jiva of the sweetness and bliss associated with bhakti. Bhakti is thus not a means to mukti but an end to itself, and this is strongly emphasised in Ekasarana writings----Madhavdeva begins his Namaghosha with an obeisance to devotees who do not prefer mukti. This identity between the jivatma and Narayana is beautifully expressed by Sankaradeva through the words of the Vedas in the 'Veda Stuti' (The Prayer of the Vedas) section of his Kirttana Ghos?, jiva amse Tumi pravesil? g?ve g?ve:-
We, all creatures, constitute a part of Thine. Thy maya, Oh Lord, keeps us in bondage; give us instruction so that we may adore Thy Feet and remove the fetters of maya through Sravana and Kirttana. 
Maya or nescience in Sankaradeva is seen as a barrier to the Lord's bhakti (Devotion). And therefore, to break the fetters of maya, is prescribed the path of adoration (bhajana) of the Lord solely through the listening to (Sravana) and recitation (Kirttana) of His Glories, taking sole-refuge (Eka-Sarana) in Him, in the company of His (single-minded) devotees (bhaktas):-
From these words of Bhagavanta (God), by taking Eka-Sarana in Him, one gains the Lord's favour and is [thus] able to effortlessly understand m?y? (nescience) and [also] liberate oneself from it. [Sankaradeva, Bhakti-Ratn?kara, M?y?taranop?ya' ('Way to Release From M?y?'), the 36th M?h?tmya]
Narayana often manifests through avatars, and Krishna is considered as the most perfect one who is not a partial manifestation but Narayana himself. It is in the form of Krishna that Narayana is usually worshiped. The description of Krishna is based on the one in Bhagavat Puran, as one who resides in Vaikuntha along with his devotees. Thus the worshipful form is different from other forms of Krishna-based religions (Radha-Krishna of Caitanya, Gopi-Krishna of Vallabhacharya, Rukmini-Krishna of Namadeva and Sita-Rama of Ramananda). The form of devotion is infused with the dasya and balya bhava in the works of Sankardev and Madhabdev. Madhura bhava, so prevalent in the other religions, is singularly absent here.
The cari vastu or the Four Reals defined this religious system. They are:
The single most important religious text is the Bhagavata, especially the Book X (Daxama). This work was transcreated from the original Sanskrit Bhagavata Purana to Assamese in the 15th and 16th centuries by ten different individuals, but chiefly by Srimanta Sankardev who rendered as many as ten Cantos (complete and partial) of this holy text.
The religion fissured into four sanghati (samhatis or sub-sects) soon after the death of Srimanta Sankardeva. Sankardev handed down the leadership to Madhabdev, but the followers of Damodardev and Harideva did not accept Madhabdev as their leader and formed their own group (Brahma sanghati). Madhabdeva at the time of his death did not name a successor. After his death three leaders formed their own denominations: Bhabanipuria Gopal Ata (Kaal sanghati), Purushuttom Thakur Ata, a grandson of Sankardev (Purusa sanghati) and Mathuradas Burhagopal Ata (Nika Sanghati). They differ mostly in the emphasis of the cari vastus (four fundamental principles)
Krishna was the all-supreme God of adoration for him