One can understand the Supreme Personality of Godhead when one is even slightly favored by Him; otherwise, without His mercy, a man may speculate for thousands of years and not understand what is actually the Absolute Truth
SB Canto 3
We know that You are the Supreme Absolute Truth, the Personality of Godhead, who manifests His transcendental form in the uncontaminated mode of pure goodness. This transcendental, eternal form of Your personality can be understood only by Your mercy, through unflinching devotional service, by great sages whose hearts have been purified in the devotional way.
The Absolute Truth can be understood in three features—impersonal Brahman, localized Paramātmā, and Bhagavān, the Supreme Personality of Godhead. Here it is admitted that the Supreme Personality of Godhead is the last word in understanding the Absolute Truth. Even though the four Kumāras were instructed by their great learned father, Brahmā, they could not actually understand the Absolute Truth. They could only understand the Supreme Absolute Truth when they personally saw the Personality of Godhead with their own eyes. In other words, if one sees or understands the Supreme Personality of Godhead, the other two features of the Absolute Truth—namely impersonal Brahman and localized Paramātmā—are also automatically understood. Therefore the Kumāras confirm: "You are the ultimate Absolute Truth." The impersonalist may argue that since the Supreme Personality of Godhead was so nicely decorated, He was therefore not the Absolute Truth. But here it is confirmed that all the variegatedness of the absolute platform is constituted of śuddha-sattva, pure goodness. In the material world, any quality—goodness, passion or ignorance—is contaminated. Even the quality of goodness here in the material world is not free from tinges of passion and ignorance. But in the transcendental world, only pure goodness, without any tinge of passion or ignorance, exists; therefore the form of the Supreme Personality of Godhead and His variegated pastimes and paraphernalia are all pure sattva-guṇa. Such variegatedness in pure goodness is exhibited eternally by the Lord for the satisfaction of the devotee. The devotee does not want to see the Supreme Personality of Absolute Truth in voidness or impersonalism. In one sense, absolute transcendental variegatedness is meant only for the devotees, not for others, because this distinct feature of transcendental variegatedness can be understood only by the mercy of the Supreme Lord and not by mental speculation or the ascending process. It is said that one can understand the Supreme Personality of Godhead when one is even slightly favored by Him; otherwise, without His mercy, a man may speculate for thousands of years and not understand what is actually the Absolute Truth. This mercy can be perceived by the devotee when he is completely freed from contamination. It is stated, therefore, that only when all contamination is rooted out and the devotee is completely detached from material attractions can he receive this mercy of the Lord.