Chaitanya, the founder of the great Vaishnava sect of Bengal, was the son of a high-caste Brahman of Nadiya, the famous Bengal seat of Sanskrit learning, where he was born in 1485, two years after the birth of Martin Luther, the German reformer.
In the doctrine of this Vaishnava prophet, the adualistic theory of Sankara is resorted to as justifying a joyful and voluptuous cult of the deity.
And accordingly it is exactly in connexion with these two incarnations of Vishnu, especially that of Krishna, that a new spirit was infused into the religious life of the people by the sentiment of fervent devotion to the deity, as it found expression in certain portions of the epic poems, especially the Bhagavadgita, and in the Bhagavatapurana (as against the more orthodox Vaishnava works of this class such as the Vishnupurana), and was formulated into a regular doctrine of faith in the Sandilya-sutra, and ultimately translated into practice by the Vaishnava reformers.
The first successful Vaishnava reaction against Sankara's reconstructed creed was led by Ramanuja, a southern Brahman of the 12th century.
As regards Vishnu, the epic poems, including the supplement to the Mahabharata, the Harivamsa, supply practically the entire framework of legendary matter on which the later Vaishnava creeds are based.
In the Vaishnava camp, on the other hand, the cult of Krishna, and more especially that of the youthful Krishna, can scarcely fail to exert an influence which, if of a subtler and more insinuating, is not on that account of a less demoralizing kind.
Madh y a Acharya, another distinguished Vedanta teacher and founder of a Vaishnava sect, born in Kanara in A.D.
The high-caste Brahman will probably keep at his home asalagram stone, the favourite symbol of Vishnu, as well as the characteristic emblems of Siva and his consort, to both of which he will do reverence in the morning; and when he visits some holy place of pilgrimage, he will not fail to pay his homage at both the Saiva and the Vaishnava shrines there.
Ramanuja's doctrine, which is especially directed against the Linga-worship, is essentially based on the tenets of an old Vaishnava sect, the Bhagavatas or Pancharatras, who worshipped the Supreme Being under the name of Vasudeva (subsequently identified with Krishna, as the son of Vasudeva, who indeed is credited by some scholars with the foundation of that monotheistic creed).
Although the Vaishnava sects hitherto noticed, in their adoration of Vishnu and his incarnations, Krishna and Ramachandra, usually associate with these gods their Brot wives, as their saktis, or female energies, the sexual element is, as a rule, only just allowed sufficient scope to enhance the emotional character of the rites of worship. In some of the later Vaishnava creeds, on the other hand, this element is far from being kept within the bounds of moderation and decency.