The essence of puja or worship as holy Hindu activity according to the Veda

The following presents a brief summary about God, as the object of worship and holy offerings and as the apportioner of fruits (including moksha), and the need / ethics associated with worshipper (Ref. 1 & 2).

God:  Hinduism is a monotheistic religion with one God (Brahman) assuming many forms and names. Brahman, as Nirguna, has no attributes (is formless and unmanifested), whereas as Saguna (or Iswara) is manifested and with attributes. People use many different names for God during worship and otherwise. Consider the following Vedic hymns,  

"They call him Indra, Mitra, Varuna, Agni, and he is heavenly nobly-winged Garutman.
To what is One, sages give many a title they call it Agni, Yama, Matarisvan." Rig Veda (Book 1, Hymn 164.46)  

"He in his might surveyed the floods containing productive force and generating Worship.
He is the God, and none beside him. What God shall we adore with our oblation?" Rig Veda (Book 10, Hymn 121.  

True bhakti (devotion) and the type (method) of worship to God depend on a person's nature and temperament. Moreover, even if the object of adoration remains the same, there may be several ways to approach it. In addition, Brahman as Nirguna (unmanifested) is simply believed in.
The direct worship of Nirguna Brahman is not possible, because it is not known (as Nirguna) and therefore cannot be worshipped. The believer therefore simply recognizes the entire creation as a reflection of God and acts accordingly (The Bhagavad Gita: Ch 12).  

In the case of Saguna Brahman, there are two types of worship -- one is of a personal God as the Immanent, and the other by using symbols. In case of the Immanent, worship usually occurs in the form of pure meditation and at the spiritual level. On the other hand, when a worshipper views God as being external to him, then the worship is symbolic. Here, symbols (objects and deities etc.) used are generally prakrit (comprising of prakrti / nature and therefore involving three modes or gunas -- sattva, rajas, and tamas). Note that the worshipper in this case needs to be careful as to what exactly the object of adoration (such as the deity) and the method of worship (yajna etc.) stand for, because that will determine the outcome (fruits) of such worship.  

Note that the personality or symbol used as a deity in meditation or worship is mainly for spiritual significance and to reflect the real power (God) behind it. Physical and material aspects of the symbol used in worship are less important.  

The deities, representing Brahman, are the medium to make prescribed offerings during puja (worship) according to different needs and sacrificers (devotees). Though the deities are seen as possessing some sort of reality, the sacrificer is urged also to pay attention to the mantras and look beyond the person of the deity. Thus, it is insisted that making offerings to the deities, while also concentrating on the accompanying mantras (addressed to them) -- which may elaborate the ultimate truth -- is rewarding. Note also that the glorification (adulation, worship) of any person (human) in the presence of the deity is not recommended. God or Brahman is basically the creator as well as the apportioner of the fruits.

The object of meditation (worship), deity, is beyond or above the Law of Karma. It should not become part of the sansara (world) -- as a soul or the constituent matter -- and not be existing at times in the mode of darkness or ignorance (Tamas). Note, only Brahman is above and beyond Karma, is changeless, and meets these conditions (The Bhagavad Gita: Ch. 5 - V. 29). On the other hand, if the meditation (worship) is intended towards a secondary figure (such as a guru or a deity) who is subject to the Law of Karma, the results from such effort will also be secondary (The Bhagavad Gita: Ch. 9 - V. 25). The meditation (worship) symbols and methods should therefore be selected properly.  

Note also that the religious offerings and gifts, though important, are voluntary and motivated by faith and love. Moreover, worships and rituals should not be performed miserly and with a desire for vainglory (Rig Veda: Book 7 - Hymn 32.9; The Bhagavad Gita: Ch. 9 - V. 26, Ch. 16 - V. 17, Ch. 17 - V. 13).  

Moksa:  Liberation is defined as "the absolute cessation of the body (or cycle of birth), caused by the disappearance of all dharma and adharma." Liberation thus consists in the total disappearance of dharma and adharma, whose operation is the cause of rebirth.

The individual, finding that in samsara (world) pleasures are mixed up with pain, turns his attention to liberation. Mere knowledge cannot give freedom from bondage, which can be attained only by the exhaustion of action. Knowledge prevents further accumulation of merit and demerit. Note that karma, in expectation of reward, leads to further birth. A person's likes and dislikes determine his future existence. He must break through the circle if he wants to attain release. Liberation is the cessation of pleasure as well as of pain. Moksa is simply the natural form of the soul and represents the state of atman in itself, free from all pain.

Ethics:  The essential component in gaining most spiritually and otherwise, through puja / worship and other pursuits, is on the ethical side, including ethical living and working (earning) comprising good, moral behavior and conduct. The ultimate reality of the world is looked upon as the constant principle of karma. God is righteousness or dharma. The contents of dharma are embodied in the Vedas, and the Vedas reveal the mind of God. While the sacrificial works may be considered as the special causes of bliss, God is the general cause.  

The Vedic injunctions lay down the details of dharma. Good action is what is prescribed by the Veda (including the Upanisads). The smrti texts (documents on traditions or customs) are supposed to have corresponding sruti texts (Vedas). If certain smrti is known to have no matching sruti, it indicates that either the corresponding sruti was lost over time or the particular smrti is not authentic. Moreover, if the smrtis are in conflict with the sruti, the formers are to be disregarded. When it is found out that the smrtis are laid down with a selfish interest, they must be thrown out. Next to the smrtis is the practice of good men or customs. The duties which have no scriptural sanction are explained on principles of utility. If any act is performed in response to one's response to natural instincts, there is no virtue in it. Vedas (sruti texts, including Upanisads) are open equally to all, irrespective of gender, varna, caste or vocation.  

To gain salvation, the observing of nitya karmas (regular or daily duties) and naimittika karmas (duties on a special occasion) are recommended. These are unconditional obligations, not fulfilling of which incurs sin (pratyavaya). To gain special ends, kamya (optional) karmas are performed. Thus, by keeping clear of kamya karmas, one frees himself from selfish ends, and if he keeps up the unconditional (nitya and naimittika) duties he attains salvation.  

Acts are enjoined with a view to their fruits. There is a necessary connection between the act and its result. An act performed today cannot affect a result at some future date unless it gives rise before passing away to some unseen result. Jaimini, in the Purva Mimamsa, assumes the existence of such an unseen force, which he calls apurva, Apurva thus is the metaphysical link between work and its result and may be regarded either as the imperceptible antecedent of the fruit, or as the after-state of the act. Apurva also comes into play / consideration during creation by God.  

(1)    Subhash C. Sharma, "BRAHMAN (God) in Hinduism," Feb. 24, 2004,        http://web.archive.org/web/20090809230806/http://geocities.com/lamberdar/brahman.html  

(2)   Subhash C. Sharma, "The Purva Mimamsa philosophy," May 25, 2004,       http://web.archive.org/web/20090809230813/http://geocities.com/lamberdar/purva_mimamsa.html

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