The source of all knowledge is Divinity. And not enough is being said about that. People are all working on emotion, emotion, emotion, you know, because they are looking at it only as a human problem. Okay, it's no problem. It's a manifestation, see, from the unmanifest rasa, the essence, the flavor of Divinity, which is ananda.
All emotion is a reduction in the quantum of ananda.
All negative emotion is a warping and a knotting in the reduced quanta of ananda. That is the definition. And bhakti is reversing the process to the Supreme Emotion. Reversing those quanta back to their Supreme Source. Reversing the reduced quanta of ananda back to the Supreme Ananda is bhakti, devotion.