"In Vedanta-sutra it is stated, anandamayo 'bhyasat: God is anandamaya, full of bliss and pleasure. Since we are part and parcel of God, we also possess these same qualities. So the goal of our yoga process is to join with the supreme anandamaya, Sri Krsna, to join His dance party. Then we will be actually happy."
Path of Perfection, Chapter 1
The Absolute Truth is anandamaya (desiring to increase His joy), hence from His original form He expands and becomes many. These emanations from the Supreme Person are of two categories: full expansions and partially manifestive expansions. The Lord's various full and partial expansions and the Lord Himself simultaneously co-exist, only appearing to manifest under the influence of time. These expansions of the Supreme Being are known as Vishnu-tattva, and they are also Supreme Absolute Truth. While non-different from the Lord, the Vishnu-tattvas all accept their own role as Godhead in the mood of Servitor to the "original" Supreme Being. This relationship is the foundation of Vedic monotheism, which encompasses the inconceivable, absolute personal nature of the original Godhead.
The Supreme Being possesses two other expansive qualities known as Shiva-tattva and jiva-tattva. Together with Vishnu-tattva, these three qualities are representative of the Absolute Person's internal, external and marginal energies. The Lord has expanded Himself as Lord Shiva and Lord Brahma, and we, the living entities, are also expansions. Like us, Lord Brahma is also jiva-tattva. Lord Siva is between visnu-tattva and jiva-tattva. And Lord Visnu is visnu-tattva. Visnu-tattva, via media, and jiva-tattva - they are all expansions of the Supreme Personality of Godhead.
"Learned scholars in transcendental subjects have carefully analyzed the summum bonum Krsna to have sixty-four principal attributes. All the expansions or categories of the Lord possess only some percentages of these attributes. But Sri Krsna is the possessor of the attributes cent percent. And His personal expansions such as svayam-prakasa, tad-ekatma up to the categories of the avataras who are all visnu-tattva, possess up to ninety-three percent of these transcendental attributes. Lord Siva, who is neither avatara nor avesa nor in between them, possesses almost eighty-four percent of the attributes. But the jivas, or the individual living beings in different statuses of life, possess up to the limit of seventy-eight percent of the attributes. In the conditioned state of material existence, the living being possesses these attributes in very minute quantity, varying in terms of the pious life of the living being. The most perfect of living beings is Brahma, the supreme administrator of one universe. He possesses seventy-eight percent of the attributes in full. All other demigods have the same attributes in less quantity, whereas human beings possess the attributes in very minute quantity. The standard of perfection for a human being is to develop the attributes up to seventy-eight percent in full. The living being can never possess attributes like Siva, Visnu or Lord Krsna. A living being can become godly by developing the seventy-eight-percent transcendental attributes in fullness, but he can never become a God like Siva, Visnu or Krsna. He can become a Brahma in due course."
Srimad-Bhagavatam 1:3:28 Purport
Bhaktivedanta Book Trust. Excerpted from text and purport of HDG A.C. Bhaktivedanta Swami Srila Prabhupada.