Vaidhi-sadhana and deity worship

There are certain prescribed methods for employing our senses and mind in such a way that our dormant consciousness for loving Kṛṣṇa will be invoked, as much as the child, with a little practice, can begin to walk. One who has no basic walking capacity cannot walk by practice. Similarly, Kṛṣṇa consciousness cannot be aroused simply by practice. Actually there is no such practice. When we wish to develop our innate capacity for devotional service, there are certain processes which, by our accepting and executing them, will cause that dormant capacity to be invoked. Such practice is called sādhana-bhakti.

Every living entity under the spell of material energy is held to be in an abnormal condition of madness. In Śrīmad-Bhāgavatam it is said, “Generally, the conditioned soul is mad, because he is always engaged in activities which are the causes of bondage and suffering.” The spirit soul in his original condition is joyful, blissful, eternal and full of knowledge. Only by his implication in material activities has he become miserable, temporary and full of ignorance. This is due to vikarma. Vikarma means “actions which should not be done.” Therefore, we must practice sādhana-bhakti—which means to offer maṅgala-ārati (Deity worship) in the morning, to refrain from certain material activities, to offer obeisances to the spiritual master and to follow many other rules and regulations which will be discussed here one after another. These practices will help one become cured of madness. As a man’s mental disease is cured by the directions of a psychiatrist, so this sādhana-bhakti cures the conditioned soul of his madness under the spell of māyā, material illusion.

— NoD chapter 2