Why Only The Bhāgavata Dharma Is Eternal? by Srila Bhaktivinod Thakura
“Devotional service to Sri Hari is known as Suddha vaiṣṇava dharma, Nityādharma, Jaiva-dharma, Bhāgavata-dharma, Paramātma-dharma and Para-dharma. The religious principles that have arisen from the predisposition towards Brahman and Paramātmā are temporary. There is a motive behind the search for the impersonal Brahmān, therefore it is causal, and hence temporary. A conditioned soul trying to achieve freedom from material bondage takes shelter of temporary religious principles in the way of pursuing the impersonal Brahmān.
Therefore the predisposition towards Brahmān is causal and not eternal. Similarly, a living entity who meditates on the Supersoul to achieve happiness derived from samādhi is following temporary religious principlesdue to his coveting subtle material enjoyment within his mind. Thus the predisposition towards Paramatma is also not eternal. Only pure Bhāgavata Dharma, aimed at simply pleasing Lord Hari is eternal.”
— Chapter 4, Jaiva-dharma, Translated by Bhaktivedanta Book Trust, Int. & Sarvabhāvana dāsa.