Bhakti is considered to be many things: A religious devotion that anyone can experience and cultivate, a system of yoga which involves specific practices and disciplines, a path to enlightenment which seeks experiences that refine feelings and open the heart to universal love. Bhakti can also mean, simply, an intense love of God. Bhaktas are those spiritual aspirants who approach enlightenment through devotion to God. They are also called devotees. By ancient tradition, devotion can be directed to any form of the Divine (Saguna) or a formless ideal (Nirguna).
Bhakti is a necessary aspect of any tradition or teaching that aspires to self-realization or enlightenment. This is because bhakti is necessary for an open heart. An open heart is necessary for direct experience. Direct experience is necessary for real knowledge. Bhakti is necessary for real knowledge.
There is a Vedic saying, “Knowledge of the books stays in the books.” For knowledge to be real it must be experienced. A closed heart cannot experience, discern and know the subtle and living energy that is the essence of Vedic knowledge. If one engages in spiritual practices with a closed heart, they will bear no or very little fruit. If one engages in spiritual practices with an open heart, any path will soon bear fruit.
The purpose of bhakti is to open the heart of the devotee and prepare it for direct experience of the divine.