sarvopādhi-vinirmuktaṁ tatparatvena nirmalam hṛṣīkeṇa hṛṣīkeśa- sevanaṁ bhaktir ucyate [Brs. 1.1.12]

When one's senses are pure, one can render loving devotional service to Krsna. A pure devotee can only remember Krsna's transcendental qualities. Remembering them, he fully engages in the loving service of the Lord.