CC Madhya 6.89
vastu-tattva-jñāna haya kṛpāte pramāṇa
Gopīnātha Ācārya replied, “Knowledge of the summum bonum, the Absolute Truth, is evidence of the mercy of the Supreme Lord.”
Sārvabhauma Bhaṭṭācārya informed his brother-in-law, Gopīnātha Ācārya, “The Supreme Personality of Godhead may not have shown mercy to me, but what is the proof of His having shown it to you? Kindly let us know about this.” In reply to this, Gopīnātha Ācārya said that the summum bonum, the Absolute Truth, and His different potencies are identical. Therefore one can understand the substance of the Absolute Truth by the manifestation of His different potencies. The summum bonum includes all potencies in one unit. The Absolute Truth combined with different characteristics is the original substance (vastu): parāsya śaktir vividhaiva śrūyate.
Thus the Vedas state that the Absolute Truth has different potencies. When one understands the characteristics of the potencies of the Absolute Truth, one is aware of the Absolute Truth. On the material platform as well, one can understand the substance by the manifestation of its symptoms. For example, when there is heat, it is to be understood that there is fire. The heat of the fire is perceived directly. The fire may not be visible, but one can search out the fire by feeling heat. Similarly, if one can perceive the characteristics of the Absolute Truth, we can know that he has understood the substance of the Absolute Truth by the mercy of the Lord.
In the Bhagavad-gītā (7.25) it is said, nāhaṁ prakāśaḥ sarvasya: the Supreme Personality of Godhead reserves the right of not being exposed to everyone. Sevonmukhe hi jihvādau svayam eva sphuraty adaḥ: “The Lord reveals Himself to a devotee when He is completely satisfied by the devotee’s service.” Thus one cannot understand the Supreme Lord without His mercy. The Absolute Truth cannot be understood by speculation, and this is the conclusion of the Bhagavad-gītā.