It co-arose with an advancing theism (a focus on the gods) in the later half of the first millennium BCE, as worship took the form of individualized devotional practice.
This form of Bhakti Yoga was the householder counterpart to the evolving spiritual arts within sramana culture—the culture of the yogis.
The bhakti tradition was driven by a sense that the gods were right at hand and responsive to everyone individually. This was a new understanding that hedged itself against priestcraft and temple protocol.
The later Upanishads reflect this emphasis. We see the multiform aspect of the godhead affirmed and, as the Common Era dawns (dated after Christ’s birth) we see the elevation of these gods to universal status–i.e. they take on the role of the Creator, the High God, the One God behind all higher divine identities.
The Bhagavad Gita provides new opportunities within this relationship–most notably the formulation of Karma Yoga. It fully introduces the concept of a bhakta being the object of a God’s personal love and affection. The book details the god Krishna’s profound personal affection for the warrior, Arjuna.
The Bhagavad Gita reveals that the relationship between human and divine is intimate.
This evolves into an acceptance of the idea that divinity rests within us all.
The striving yogis could attain godhood, but with the coming of the Tantras, it was explained that we are already liberated, and that we exist as emanations of The One.
This great conceptual leap in Indian religiousity taken by the Tantras was foreshadowed in the Vedas, most specifically in the stories of the yogi-like Kesins (“long hairs”) of the Rig Veda, who were “friends with this god and that god.”
The cults of Tantra settled both householders and yogis into the seat of divinity by claiming that the identity of initiated practitioners was Shiva himself.
The close association with the Gods that found potent expression in the Gita and in the deity tales of the Puranas (the sacralized stories of the gods that were composed in the early Common Era—contemporary with the Gita) comes back around in the Tantric equalization of human and divine natures.
Recognition of this equality has the potential to utterly annihilate life’s banality. Tantra assigns us divine status. And it electrifies our world.