Bhakti yoga is the Hindu term for the spiritual practice of fostering of loving devotion to God, called bhakti Traditionally there are 9 forms of bhakti yoga. Hindu movements in which bhakti yoga is the main practice are called bhakti movements.
The Philosophy and Development of Bhakti
Bhakti (Hindi) signifies a blissful, selfless and overwhelming love of God as the beloved Father, Mother, Child, or whatever relationship finds appeal in the devotee's heart. The philosophy of Bhakti seeks to tap into the universal divinity through personal form, which explains the proliferation of so many Gods and Goddesses in India, often reflecting the personal inclinations of small regions or groups of people. Seen as a form of Yoga, or union, it seeks to dissolve the ego in God, since consciousness of the body as self is seen to be a divisive factor in spiritual realization. Essentially, it is God who effects all change, who is the source of all works, who acts through the devotee as love and light. 'Sins' and evil-doings of the devotee are said to fall away of their own accord, the devotee shriven, the sins even transcended, through the love of God. The Bhakti movements, which followed the establishment of the three Vedanta systems, rejuvenated Hinduism through their deep expression of faith and responsiveness to the philosophical and emotional needs of India, illustrated by Bharatanatyam and can rightly be said to have affected the greatest wave of change in Hindu prayer and ritual since the advent of Adi Shankaracharya.
Adoration and loving devotional worship of a personal god (Bhakti) is an inherent part of most religious traditions. However, in Hinduism, an entire philosophy and system of thought dedicated to it developed into an arguably independent force of its own, drawing but otherwise separate from other movements within Sanatana Dharma. The earliest idea of salvific devotion through love is amply demonstrated in the worship of the early Rig Vedic god Varuna. This early Vedic attempt at monotheism (not monism, which saw its beginnings in the Vedas and thorough explication in the early Upanishads of 1500-1000 BCE) was later realized in post-Upanishadic movements that sought to, as Shri Ramakrishna once put it, embrace the Lotus Feet of the one loving Lord.
Varuna: the prototype of Bhakti?
A recognized twentieth century expert on Indian Philosophy, S. Radhakrishnan, a professor at Oxford University and once-President of India, wrote this of Varuna in his book Indian Philosophy, Volume 1:
"The theism of the Vaishnavs and the Bhagavatas, with its emphasis on bhakti, is to be traced to the Vedic worship of Varuna, with its consciousness of sin and trust in divine forgiveness."
Varuna is indeed seen, unlike many of the other more capricious personalities, as a morally righteous and benevolent God, encompassing all others and ready to forgive the transgressions of the devotee.
The Bhagvad Gita
While it has an extensive list of philosophical and religious associations, the Bhagvad Gita is also seen as a cornerstone for Hindu Bhakti theism, especially Vaishnav. However, it has been interpreted by many as being a manual not limited just for Krishna. Whatever be the case, it is adamant, in Krishna's words, that love and innocent, pure intention is the most powerful motive force in a devotee's spiritual evolution. It is a very succinct and comprehensive statement on the mindset of the Bhakta (loving devotee), regardless of the form of God chosen.
On Bhakti Yoga, the Gita states: ";.... those who, renouncing all actions in Me, and regarding Me as the Supreme, worship me... of those whose thoughts have entered into Me, I am soon the deliverer from the ocean of death and transmigration, Arjuna. Keep your mind on Me alone, your intellect on Me. Thus you shall dwell in me hereafter." --(B.G., Chapter 12, Verses 6-8)
The philosophical schools changed the way people thought, but Bhakti was immediately accessible to all, calling to the instinct emotion of love and redirecting it to the highest pursuit of God and self-realization. In general a liberal movement, its denouncement of caste offered recourse for Hindus from the orthodox Brahaminical systems. Of course, however, Bhakti's message of tolerance and love was not often heeded by those ensconced in the societal construct of caste. Altogether, Bhakti resulted in a mass of devotional literature, music and art that has enriched the world and gave India renewed spiritual impetus, one eschewing unnecessary ritual and artificial social boundaries.