"Your constitutional position is that you are pure living soul," the Lord told Sanātana. "Your material body is not your real self, nor is your mind your real identity, nor your intelligence, nor your false ego. Your identity is that of an eternal servitor of the Supreme Lord, Kṛṣṇa. Your position is that you are transcendental. The superior energy of Kṛṣṇa is spiritual in constitution, and the inferior, external energy is material. Since you are between the material energy and the spiritual energy, your position is marginal. Belonging to the marginal potency of Kṛṣṇa, you are simultaneously one with and different from Him. Because you are spirit, you are not different from Kṛṣṇa, but because you are only a minute particle of Kṛṣṇa, you are different from Him."
This simultaneous oneness and difference always exists in the relationship between the living entities and the Supreme Lord. From the fact that the living entities are always in the marginal position, this conception of "simultaneously one and different" can be understood. The living entity is just like a molecular particle of sunshine, whereas Kṛṣṇa is like the blazing sun itself.