There are two stages of God realization. One is called sujñeyam, or very easily understood (generally by mental speculation), and the other is called durjñeyam, understood only with difficulty. Paramātmā realization and Brahman realization are considered sujñeyam, but realization of the Supreme Personality of Godhead is durjñeyam. As described here, one attains the ultimate realization of the Personality of Godhead when one gives up the activities of the mind—thinking, feeling and willing—or, in other words, when mental speculation stops. This transcendental realization is above susupti, deep sleep. In our gross conditional stage we perceive things through material experience and remembrance, and in the subtle stage we perceive the world in dreams. The process of vision also involves remembrance and also exists in a subtle form. Above gross experience and dreams is susupti, deep sleep, and when one comes to the completely spiritual platform, transcending deep sleep, he attains trance, viśuddha-sattva, or vasudeva-sattva, in which the Personality of Godhead is revealed.
Ataḥ śrī-kṛṣṇa-nāmādi na bhaved grāhyam indriyaiḥ: (CC Madhya 17.136) as long as one is situated in duality, on the sensual platform, gross or subtle, realization of the original Personality of Godhead is impossible. Sevonmukhe hi jihvādau svayam eva sphuraty adaḥ: but when one engages his senses in the service of the Lord—specifically, when one engages the tongue in chanting the Hare Kṛṣṇa mantra and tasting only Kṛṣṇa prasāda with a spirit of service—the Supreme Personality of Godhead is revealed. This is indicated in this verse by the word śuci-sadmane. Śuci means purified. By the spirit of rendering service with one's senses, one's entire existence becomes śuci-sadma, the platform of uncontaminated purity. Dakṣa therefore offers his respectful obeisances unto the Supreme Personality of Godhead, who is revealed on the platform of śuci-sadma. In this regard Śrīla Viśvanātha Cakravartī Ṭhākura quotes the following prayer by Lord Brahmā from the Śrīmad-Bhāgavatam (SB 10.14.6): tathāpi bhūman mahimāguṇasya te viboddhum arhaty amalāntar-ātmabhiḥ. "One whose heart has become completely purified, my Lord, can understand the transcendental qualities of Your Lordship and can understand the greatness of Your activities."