So, svayaṁ bhagavān, Kṛṣṇa, kṛṣṇas tu bhagavān svayam (SB 1.3.28). We have many times explained the word bhagavān. Bhagavān means six opulences: riches and . . . aiśvaryasya samagrasya vīryasya, potency; vīryasya yaśasaḥ, fame, reputation; aiśvaryasya samagrasya vīryasya yaśasaḥ śriyaḥ (Viṣṇu Purāṇa 6.5.47), beauty; jñāna, knowledge; and vairāgya, detachment.
When one is full with all these six opulences, He's God. So people try to get the opulences. Everyone is trying by karma, jñāna, yoga. But nobody can attain the opulences in full strength. That is not possible. So the simple definition of God is that one who is in full six opulences, He's God. That has been analyzed by great saintly persons, including Lord Brahmā, and it has been decided that the all the six opulences can be found in Kṛṣṇa.