Bhakti yoga is a process in which your emotions are involved and your awareness is directed and dedicated to a higher Being. This higher Being may be the ishta devata, your Guru, a saint, atman, the Self, or formless time and space. Whenever your tendencies and mind are directed towards the subtle spheres of existence and are completely dedicated towards that, it is known as bhakti. When the same tendencies flow to the outside through the senses (indriyas), either for positive or negative aspects (shuddha or ashuddha), that is known as chitta vritti (modifications of the Self). When you are cruel, unkind and hateful and are dedicated to harming others, that is a negative form of Love. Remember, love means "total awareness".
If you love the Divine Being or God the Almighty, your love is consumed in totality; It is not subject to reaction. Therefore, Bhakti yoga is the redirection of love from matter to spirit. You sing the name of the Supreme Being, you repeat His name, you think of His glories and greatness, and you try to keep Him in your heart and mind all the time, as you generally do with the ordinary things of life.
When your heart and mind are given in attachment to the things of the world, then you feel pain, agony and disappointment; there is always separation, but when you dedicate your mind to God, or a divine Being then you find total satisfaction, and at the same time, an experience of fulfilment.
Bhakti yoga is the highest culmination in man's life, and if bhakti happens to manifest in you naturally even without listening to me or reading the "Gita" or "Ramayana", then you have reached the summum bonum of earthly life. You have come to the climax of human evolution!
Bhakti is not as easy or as ordinary as most of us have been led to believe. In fact, I have found bhakti extremely difficult- It cannot be taught, it has to be inborn. You cannot become an intellectual bhakta, and that is where most of us are failing. Everything in this world can be learned, and you can attain nirvikalpa samadhi without much difficulty, but it is hard to develop a speck of bhakti. It is an experience that will completely transport you from this plane to that other of experience within a trice. It does not take years or months, but just a few seconds.
How can bhakti be developed? Ramakrishna has said, "One will have to re-divert the totality of one's experience, only then will it happen. As yon love your wife or husband, your child or mother, or your wealth and property, yourself and your life, that total love will have to be directed to God. Then He will be here and now". For a gyani, God is nowhere, but for a bhakta, God is here and He is everywhere. The concept of bhakti completely transforms every speck of existence and then you are not a mere man.
Now, in the early stage of bhakti, you must remember that duality exists. There is the lover and there is the beloved. This dwaita, or duality is something that bhaktas do not want to part with.
Lord Krishna, who is known as Yogeshwara, the Lord of Yoga, once sent his disciple Uddho to Gokul to conduct yoga classes for the Gopis. When Uddho met the Gopis they asked, "How is Krishna and why have you come?" Uddho replied, "Do not worry about Krishna, I have come to teach you Yoga. We shall start tomorrow". The cleverest of the Gopis asked, "Which yoga are you going to teach us? We have only one mind and one awareness and they have gone to Dwarika where Krishna is, so which mind are you going to train?". If your mind is as one-pointed as the Gopis', what need have you for any other form of yoga?