The complete knowledge, Absolute Truth, means to understand three features of the Absolute Truth. One feature is Brahman, impersonal. The next feature is Paramātmā, localized. And the next feature is Bhagavān, the Supreme Personality of Godhead. When one understands these three features of the Absolute Truth very perfectly, then he is in complete knowledge of the science of God. Brahmeti paramātmeti bhagavān iti śabdyate.
In the Śrīmad-Bhāgavatam it is said that human life is meant for inquiring the Absolute Truth. And the next verse the Absolute Truth is explained, vadanti tat tattva-vidas tattvam (SB 1.2.11).
Those who are in knowledge of the Absolute Truth, they say: "Absolute Truth, that thing which is nondual." Nondual. "And that Absolute Truth is known in three phases." What is that? Brahman, Paramātmā and Bhagavān. There is no difference between Brahman and Paramātmā or Bhagavān, the same thing.
The same example again—just like the sunshine, the sun disc and the sun-god within the sun disk. They are the same thing, light. But there is difference of degrees. The light and temperature which you feel in the sunshine is different from the light and temperature in the sun disc. And the light or temperature in the sun disc is different from the light and temperature of the sun-god. But they are all light.
Similarly, Absolute Truth is one—light—but there are degrees. If you become attached to impersonal Brahman, you simply enjoy the eternity feature of the Absolute Truth. If you simply try to understand the Supersoul by meditation, then you realize the eternity and knowledge aspect of the Absolute Truth. But if you realize the Supreme Personality of Godhead, then you realize eternity, knowledge and bliss, three things.
Because without being connected with Kṛṣṇa, or the Supreme Personality of Godhead, there is no possibility of enjoying transcendental bliss. In the impersonal Brahman you can remain there eternally. In Paramātmā you can have knowledge. But in Bhagavān you have eternity, knowledge and transcendental bliss.
Revatīnandana: "He thus knows his constitutional position perfectly well without falsely trying to become one with the Supreme in all respects. This is called Brahman realization, or self-realization. Such steady consciousness is called Kṛṣṇa consciousness."