The Bhagavathas, in the Vedic times, developed Vaishnavism or devotional worship to Sri Vasudeva or Sri Narayana. Their own scripture was known as Pancharathra Agama, regarded as equal to Upanishads. Vaishnava Acharyas, later, combined Karma and Jnana pathways to these teachings for the realization of God. Sri Ramanujacharya wrote Sri Bhashya, his commentaries on Brahma Suthras and gave us the philosophy, as the chief text of the system of Visishta-adhvaitha. The Visishta-adhvaitha system is an ancient one. It was originally explained by Sage Bodhayana in his Vritti. It is the same as followed by Sri Ramanuja in his interpretation of the Brahma Suthra. Sri Ramanuja accepts perception, inference and Scripture as valid sources of knowledge. He adopts the theories of Sathkara-Vaada and Parinama-Vaada, the doctrine of real effect proceeding from a cause. Sri Ramanuja also wrote a commentary on Bhagavat-Gita and other books known as Vedantha Sara, Vedhantha Sangraha and Vedhantha Dipa.

Sri Ramanuja explains Brahmam as a personal God with attributes. Whatever exists, is Brahmam; but It is not of a homogenous nature. It has elements of plurality and manifests in a diversified world. There is no room for Nirguna Brahmam and Saguna Brahmam or Iswara. It is Savisesha Brahmam or Iswara with attributes. When Vedas describe Him as Nirguna, it means there is no base or lower qualities such as sorrow, pain, change or old age for Him. He is the essence of the soul and all-pervading. He is Sathya (Truth), Jnana (Knowledge) and Anandha (Bliss). He is Immanent, Transcendent and He is also unchanging. The entire Universe is latent in Him during Pralaya. The world is projected during creation, but this does not touch His essence. God, soul and Nature are three eternal entities. The soul is self-conscious, unchanging, partless and atomic. They are infinite in numbers and individual. It is eternally distinct from God. It has, indeed, sprung from Brahmam, but is never outside Brahmam and enjoys a separate personality. The individual soul is immersed in a worldliness or Samsara. It gets its body according to it's past Karma and gets reborn till the final emancipation. The liberated soul passes into a kind of paradise (Vaikuntha) which is the place of Sri Narayana.

From the ancient times, a system of religious thinking based on devotion to the Supreme Deity existed. The Bhakthi Schools worship a Personal God with devotion. Earlier the Bhakthi movement was strengthened in South India by the twelve Alvar saints, whose works were known as "Nalayira Prabhandam", a series of four thousand Tamil poems. They were mainly based on Bhakthi concept. Sri Natha Muni raised the Prabhanda to the levels of Vedas. Sri Yamunacharya laid the foundation to build the philosophy. According to Sri Sankara, Karma or path of action and Bhakthi or the pathway of devotion are the means to attain the Jnana or the pathway of wisdom, realization and supreme knowledge which is liberation or Moksha. In Sri Ramanuja's teaching, Bhakthi Pathway is the ultimate to reach God in Swarga. According to this concept, Karma, the path of action or service, and Jnana, the path of wisdom and knowledge, are only means for the Bhakthi pathway. The final emancipation can come only through Bhakthi or devotion, total surrender or Saranaagathi and receiving the grace of the Lord.

Sri Madhvacharya postulated a dualistic system, Dvaitham, out of Upanishads, Bhadavat-Gita and Brahma Suthras; which is called the Prasthana Thraya. His Vaishnavism is called Sadh-Vaishnavism, while Sri Ramanuja's is known as Sri-Vaishnavism. Their systems have many points in common. In Sri Madhva's system, Hari or Sri Vishnu is the Supreme being, also known as Narayana, who lives in Vaikunta or Swarga [Heaven] with His consort Sri Lakshmi. The world is real and the difference is true. All Jivas are dependent on Hari. Bhakthi, without faults, is the means of attaining salvation. God is the only independent reality. Souls and world are dependent reality which are separate from Him. He is the efficient cause and not material cause. No two jivas are alike. The jivas are different from God and do not attain equality with God. They are entitled only to serve Him. The grace of Lord Narayana descends on those souls who are pure, devoid of all "Upaathis".