Srila Rupa Goswami gives us a most wonderful definition of bhakti:

anyābhilāṣitā-śūnyaṁ
jñāna-karmādy-anāvṛtam
ānukūlyena kṛṣṇānu-
śīlanaṁ bhaktir uttamā

“One should render transcendental loving service to the Supreme Lord Kṛṣṇa favorably and without desire for material profit or gain through fruitive activities or philosophical speculation. That is called pure devotional service.”

In this verse Srila Rupa Goswami clearly says what actually pure bhakti means. Srila Jiva Goswami comments on this verse and he especially puts emphasis on the main characteristics which define pure bhakti:

• Anusilanam

“Anusilanam” means “continous, uninterrupted loving service”. When we start our bhakti-life, we practice “sadhana-bhakti”. We do actions to serve Krishna. Out of love and out of free will we carefully observe regulations which bring us closer to the Lord.These actions we do by body, mind and words. This kind of bhakti is called cesta-rupa-bhakti (performing all kinds of loving actions for Krishna). When our consciousness becomes more pure, we will experience wonderful emotions and feelings (moods) during our bhakti-life. We progress onwards to bhava-rupa-bhakti. What in the beginning have been actions in a kind of “mechanical” way now turn into loving service with deeply felt emotions (anubhavas).

Srila Rupa Goswami adds the word Krishna to “anusilanam”. So we then have the word “Krishnanusilanam”. All our continous, loving service throughout the stages of bhakti should be directed to Krishna and His loved ones.

• Anukulyena

These loving actions should be performed with a behaviour FAVOURABLE to Krishna. We should please Him in a very friendly mood towards Him. This is called the MAIN CHARACTERISTIC of pure bhakti. We should do everything with a most loving attitude towards Krishna.

• Anyabhilasita-sunyam and jñāna-karmādy-anāvṛtam

Our efforts to please Sri Krishna in a favourable and friendly mood should be free of other desires, dwelling in the back of our minds, than LOVE FOR GOD. And our loving service should be free of the desire for knowledge about the impersonal form of God and free of the desire for knowledge about karma-yoga (like: How to do good things to enter the heavenly planets?). We should only be concerned about the knowledge which helps us to love Krishna and about the actions which bring us nearer to Him. These are the SECONDARY CHARACTERISTICS.

In this way, Srila Rupa Goswami´s famous verse about the definition of pure bhakti is explained by Srila Jiva Goswami.