This is the first one in the list of the Upnishads and is the 40th chapter of Shukl Yajurved (sanhita) so it has its own importance. It starts with the very first word Ishwar which means the Divine personality of God.

It has only 18 verses. In its first verse it gives a condensed philosophy of God and God realization which is the gist of the Upnishadic philosophy. It says,

“The entire universe (visual and non-visual) is filled, impregnated and enveloped with the omnipresence of the Divine personality of God. All kinds of wealth of the visual world with all of its fascinating luxuries is just an illusion that does not belong to anyone. So, don’t be attached to it.Holding the personal form of God in your mind all the time, and living a renounced life, pass on the days of your life whatever good or bad comes according to your destiny

This statement establishes the philosophy of karm yog which is detailed in the Gita. Ishopnishad in this verse specifically emphasizes on remembering the personal form of God and indicates to rely on His Grace.

It has three big chapters called Shikcha Valli, Brahmanand Valli and Bhrigu Valli with their subsections. It tells more about the creation of the universe. It says,

“From Him, first, the space came into being. Then, air, fire, water and earth, and then the vegetation came into being.” (2/1) “He thought of creating the universe, and the universe was created.” (2/6) “He Himself became the universe.” (2/7)

“From Whom the universe and all the souls emerge; due to Whom all the souls sustain their life; and in Whom they enter after the total dissolution of the universe; that One is knowable and attainable, and That is brahm.” (3/1) Taittariya Upnishad further says that that brahm is eternally personified which is His prime form and He Himself (sah) is the absolute Bliss and Divine love (rasah). A soul becomes Blissful only when he receives that Bliss. (2/7)

It has six chapters and is one of the important Upnishads. It explains the definite characteristics of all the three: soul, maya and God; and also tells the definite procedure of God realization. It says,

God and the soul, both reside together in the heart of every being. Figuratively describing the human body as a tree, the Shvetashvatar Upnishad says, “Two birds, which are eternal friends, live on the same tree, whereas one bird (the soul) is enjoying eating the fruit (sensual pleasures) of that tree and the other one (God) is simply watching the first one.” (4/6) “That God is all-absolute by all means. He doesn’t have separate body, mind and soul configuration like human beings. You can say that His whole body is His soul and mind, or His body, mind and soul are all one. Nothing is equal to Him and nothing is more than Him; He is the ultimate supreme. He has many Divine powers, just like: knowledge (called chit tattva), almightiness, action (for example, the creation, maintenance and dissolution of the universe) and His most important personal power (swabhaviki) called yogmaya or ahladini shakti.” (6/8)

“Mayic creations which are deteriorative, and the souls enjoying (harah) the objects of maya, are both eternal. The one Who is above both and Who is the controller of both is supreme God. When a devotee lovingly engrosses his mind in Him and constantly remembers Him, only then his mayic bondage is broken.” (1/10) “Only after realizing Him a soul may cross the ocean of maya; there is no other way.” (3/8)

The last verse reveals the true secret of God realization. It says, “When a devotee has infallible love and devotion (bhaktih) for his beloved and Gracious God (Devah), and he is equally dedicated to his Spiritual Master (who is a God realized Saint), only then that soul (with the Grace of the Saint) perceives, conceives and understands the Divine secrets (and becomes God realized).” (6/23)

This is one of the important Upnishads revealing certain eminent issues that were mentioned in the first eleven of the 108 Upnishads, but not explained.

In the first chapter it tells that God has two forms: personal, Who has all the virtues, and impersonal, which never ever shows any virtues; and that both forms are omnipresent in the world  . If someone questions: Which one is the main form? In the second chapter it tells that, without the personal form, the impersonal form cannot exist. So, personal form of God is the main form. This theme was already mentioned in Mundakopnishad, and Shvetashvatar Upnishad,which means that only by worshipping Him and by knowing Him the mayic bondage could be eliminated because nirakar brahm is established in the sakar brahm. This is also declared in the Gita. In the eighth chapter which is the last one, it says,

“Without bhakti, brahm gyan can never be attained. Thus a soul, leaving all other practices of heart purification, should firmly stick to the path of bhakti and establish his mind only in bhakti, only in bhakti, and only in bhakti, because through bhakti one can attain anything and everything in the Divine world.”

It means, “The eternal Vaikunth, the abode of Maha Vishnu, is the eternal form of unlimited Bliss that magnificently magnifies the Blissfulness of every part of Vaikunth where all the Devotee Saints of Bhagwan Vishnu go and live forever.” The procedure, as to how a liberated soul enters the Divine abode, is described as thus in its fifth chapter:

“After God realization, when the bhakt Saint is going to enter the Divine abode, his physical body is replaced with the Divine body which is substantially the Divine Bliss itself, exactly the same as of Maha Vishnu. With that Divine body he enters Vaikunth abode.” This theme was briefly mentioned in the Kathopnishad, , which means that the God realized Saint after crossing the field of maya enters (apnoti) the Divine abode of God. The term ‘abode of God Vishnu’ is a generalized term that means the Divine abode of any personal form of God, either Vishnu or Ram or Krishn.

The statement of Taittariyopnishad, “He is the absolute Bliss or He is the Bliss of Bliss,” is further explained in Gopal Poorv Tapiniyopnishad. The word ‘rasah’ means the Bliss of the Divine Bliss, or the Divine love. This Upnishad has two chapters. In the first chapter it says,

“(1) Krishn word means the absolute and eternal Bliss; He is supreme brahm. (2) He is the supreme God (parmam daivtam). (3) Govind Krishn Himself is the eternal life, knowledge and Bliss.”

In the second chapter it reveals the topmost secret of the Divine world and says,

“Thus, only Krishn is the supreme form of God. So, remember Him (dyayet), adore Him (bhajet) and (then with His Grace) experience His Divine love (raset).” The word rasah has come only for Krishn. It has never come for Vishnu or Shiv etc. in the Upnishads. This situation clearly indicates that Krishn is the ‘Bliss of the Bliss,’ whereas Vishnu, including all other almighty forms of God, are just the form of unlimited Bliss. Thus it is evident that the almighty forms of God (like Vishnu etc.) are established in the personality of Krishn in a self-submissive style. Just like the ‘Bliss of the Bliss’ is the source of the Bliss, or you can say that the Bliss is established in its source, ‘Bliss of the Bliss.’