Examine Ourselves In Bhakti-yoga - Prabhupada 1058
710129 - Lecture SB 06.02.45 - Allahabad
In the Bhagavad-gītā it is said, pratyakṣāvagamaṁ dharmyaṁ (BG 9.2). In other methods of self-realization, namely karma, jñāna, yoga, you are not able to test whether you are actually making progress. But bhakti-yoga is so perfect that you can practically examine yourself whether you are making progress or not.
Exactly the same example, as I have repeated several times, that if you are hungry, and when you are given eatables, you can understand yourself how far your hunger is subsided and how far you are feeling strength and nourishment. You haven't got to ask anybody else. Similarly, you are chanting Hare Kṛṣṇa mantra, and the test is whether you are actually making progress is if you know whether you are being attracted by these two lower qualities of material nature, namely the modes of passion and modes of ignorance.