Pradyumna: "Generally, people are engaged in different activities to get some material profit, while most philosophers are engaged in proposing transcendental realization through volumes of word jugglery and speculation. Pure devotional service must always be free from such fruitive activities and philosophical speculations. One has to learn Kṛṣṇa consciousness, or pure devotional service..."
Prabhupāda: Yes. Jñāna-karmādy-anāvṛtam (CC Madhya 19.167). Pure devotional service should be uncovered by the motive of nirbheda-brahmānusandhana, the motive of karma and motive of jñāna. That is pure devotional service. No motive.
- anyābhilāṣitā-śūnyaṁ
- jñāna-karmādy-anāvṛtam
- ānukūlyena kṛṣṇānu-
- śīlanam...
- (Brs. 1.1.11)
Simply to do things which Kṛṣṇa wants to do, that is bhakti. That is pure bhakti.