Why they fall down? Anādṛta-yuṣmad-aṅghrayaḥ. They'll never agree God is person. They'll never agree. Their teeny brain cannot accommodate that God, the Supreme, can be a person. Because he has experience of the person of himself, or others, if God is a person like me and you, then how He can create universe . . . innumerable universes?
Therefore, to understand the Supreme Personality of Godhead it requires enough pious activities. In Bhagavad-gītā it is said, bahūnāṁ janmanām ante (BG 7.19). After speculating in the impersonal philosophical way, when one is mature, bahūnāṁ janmanām ante jñānavān, when he's actually wise . . . so long he cannot understand that the Supreme
Absolute Truth is person, sac-cid-ānanda-vigraha (Bs. 5.1), brahmeti paramātmeti bhagavān iti śabdyate. Bhagavān. That . . . vadanti tat tattva-vidas tattvaṁ yaj jñānam advayam (SB 1.2.11). This is statement in the Śrīmad-Bhāgavata: "Those who know the Absolute Truth, they know that Brahman, Paramātmā and Bhagavān, they are one. It is different phases of understanding only."