The bhakti movement was long opposed by the brahminis because it disregarded Vedic rituals, ignored caste differences (many of the bhakti saints and leaders were of the lower castes), and stressed devotion over knowledge. Calm speculation about the all-pervading Brahman was eschewed in favor of the mystical exuberance.

But, when the bhakti movement gained popularity, it quickly attracted large numbers of Brahmins. The Bhagavad Gita is the first expression of bhakti, with its concentration on the adoration of Vishnu, who appears in the work in the person of Krishna. Over the centuries this movement became powerful in South India among the Alvars, and thus throughout the entire country, developing not only Vaishnavite but also Shivite and Shakti forms. Partially the movement grew when being carried by wandering holy men through the means of song and music and the recitation of the great texts. Bhakti essentially became the religion of the masses of India, for it enables the individual to approach the Divine directly and to become a part of his all-encompassing love.

Tiru-Mular, a Shaivite poet of the Middle Ages sang: "The ignorant say love and God are different; None know that Love and God are the same. When the know that Love and God are the same; They rest in God's Love." More formal but obscure bhakti texts can state: "The nature of bhakti is absolute love for Him," and "Bhakti is supreme attachment for the Lord." The bhakti poet Nammalvar sang: "My Lord, though endless pains afflict me, I will not cease to look for thy mercy." In more recent times the saint most strongly associated with bhakti is the venerated Indian holy man known as Vallalar (aka: Ramalinga Swamigal, 1823-1874).

One of the major themes of bhakti is that of avatar, God manifesting himself on earth in some form (even animal as well as human) in order to benefit humankind in time of troubles; Krishna is often cited as the supreme example of an avatar, so too by many, the Bhagavan Sri Ramana Maharshi.

The other equally important text besides the Bhagavad Gita in presenting bhakti beliefs is the Bhagavata Purana. According to tradition its authorship is assigned to Marharshi Veda Vyasa who also is credited with the Gita, but internal and external evidence dates the Purana as being composed around the ninth or tenth century AD. The Purana, in summary, is a synthesis of many themes of various schools of bhakti, but also contains many legends, folk stories, discourses, theological and philosophical views, and scraps of unconscious anthropology and sociology centering around hundreds of avatars, saints, heroes, gods, and holy people. It has been a fertile source for many Indian films. And, there are many more works of literature, music, and art that bespeak of bhakti. Special reference may be given to Alvars, Kabir, and Mira Bai.

Besides challenging brahminical institutions, bhakti also sharply differs with some Hindu basic beliefs, especially that of Karma. This bhakti belief of Karma differs with the ordinary karmic conception of working off, or eliminating, good or evil Karma that the individual has developed, or earned, in previous lives. In the bhakti concept, Karma is set aside; the devotee expects the Lord will return Love for love and to ignore the predestined course of Karma. The question as to whether the Lord will abide by the ironclad law of Karma, or bestow his grace by removing it from the bhakti has fallen into the hand of the priestly castes, without resolution. Bhakti, like so many other aspects of the Hindu religion and life, has been categorized ad infinitum, and such categories seem to multiply within them as they are examined. But, the masses seem to ignore such scholasticism.