Concept of idol worship is a rather old concept that can be found prevalent in almost all the cultures of the world. In the Hindu Religion, its practice can be traced back to the Vedas. One of the hymns of the Rig Veda refers to the worship of Lord Vishnu. On the authority of this hymn, Sage Marichi, one of the exponents of the Vaikhanasa Agama, explains that the Vaishnavas should worship Lord Vishnu daily. On the basis of this Vedic authority Sage Saunaka also extols the worship of Vishnu. One other hymn of the Rig Veda makes an explicit mention of the worship of idol as a means of the realisation of God. The hymn states that the Purusottama who resides in the farthest place manifests Himself in the form of a log floating on the ocean of Sindhu (Indian Ocean); it is a divine form and not made by any human being (apauruseya) and by offering worship to this wooden image, one will attain the Supreme Being. That this hymn refers to the idol worship is proved by the fact that Skanda Purana, while speaking of the greatness of Jagannath (the presiding deity of the holy place, Puri) elucidates this hymn. It is not, therefore, correct to say that Vedic Religion is primarily concerned with the worship of deities in the form of yajna or sacrificial rites in the consecrated fire and that it does not allow the worship of idols.

The word yaj etymologically means worship of a deity (yaj devata pujayam). Worship is done in four ways: japa or recitation of mantras, huta or offering oblations through the sacrificial fire, archana or offering worship to an image of God and dhyana or meditation. All the four ways of worship have been observed in the Vedic times, according to the capacity of the concerned individual devotee, though more emphasis seems to have been given to yajna or huta. Even in the performance of yajna, the individual divine beings have to be invoked by reciting the appropriate Vedic hymns in a media such as kusa or blade of grass, kumbha or a water pot, agni or the sacred fire. The consecration of God in an idol prescribed by the Pancharatra Agamas through certain religious rites is similar to it. Thus, consecration of an idol with divine spirit and offering of worship to such an idol is not a non-Vedic custom. With the deterioration of the capacity of the human beings to adopt the other harder modes of worship such as yajna and dhyana the Agamas have prescribed the simpler method of image worship and developed this doctrine fully. In fact the worship in the arca form gained prominence in the Agamas. The hymns of the Alvars singing the glory of the idols in the various Vaishnava temples gave added significance to the temple worship. This explains the development of temples in an increasing way at a later period in the history of Vaishnavism.

The arca avatara which constitutes the foundation for image worship is considered more significant than the other incarnations of God. The transcendental form of God (para-rupa) is beyond the approach of human beings since it exists only in the transcendental realm. The vyuha forms too are unapproachable to us. The vibhava forms have already taken place in the remote past and as such are not available to us at present for direct worship. The presence of God as the indwelling spirit in our heart (antarydmi) though close by is also beyond the scope of worship because the physical sense organs cannot perceive Him. Thus, the Divine Being present in the form of arca vigraha is always easily available to us for offering worship. Pillai Lokacharya has explained by an analogy the five forms of manifestation of God and the unique feature of arcavatara. The Antaryami form is comparable to the underground water (bhugata-jala) implying that without the arduous eightfold yoga practice it is not possible to visualise God within, in the same way as the water in the underground cannot be obtained except with hard labour of digging the ground. Thepara rupa of God is like the vast stretch of deluge water surrounding the universe (avarana-jala) and as it exists in a realm far remote from the universe, it is absolutely inaccessible to us. The vyuha forms are compared to the mythological milky ocean which, though it exists within the cosmic universe, is unapproachable by us. The vibhava manifestations are analogous to the seasonal flood water, which comes at a particular time and useful for those living at that time but of no use for others at a later period. Only the persons, who were living during the time of the vibhavavataras, would have worshipped these divine forms but those of the future generations could not do so. The arcavataras are similar to the water present in the pools of the river bed and available at all times for a thirsty person. The icons at the temples or at homes in which the divinity is present are easily accessible to every devotee at all times. Hence, the greatness of arca idols is extolled by the Alvars and the Vaishnava acharyas .

Vaishnava literature in the later stages speaks of four types of arcavatara. These are known as svayamvyakta, daiva, saiddha and manusa. Svayarhvyakta means self-manifest, that is, God on His own manifests Himself in the form of an icon. The idols found in such temples as Srirangam, Tirupati, Badarikasrama, Vanamamalai and Melkote are said to be of this category. Daiva means those idols which have been consecrated by divine beings. That is, either in response to the prayers offered or sacrifices performed by the divine beings such as Brahma, God descends on earth in the form of an icon. The idol at Varadarajasvami temple at Conjeevaram is claimed to be of this type. The third type is known as Saiddha, which means those idols consecrated by sages. That is, in response to the penance (tapas) performed by the ardent devotees, God incarnates Himself in the form of an image. There are several Vaishnava temples in South India which are claimed to be of this category. The last one is called manusa, or what is consecrated by human beings. To provide an opportunity for the general public to offer worship, temples are constructed and idols made of stone or some other material are installed in them and the same are consecrated by means of rituals prescribed by the Agamas. Most of the Vaishnava temples of later origin and those which have been coming up in recent years fall under this category. Though every idol duly consecrated is holy and is an arca vigraha or the incarnation of God, tradition accords greater sanctity to the first three in general and to the svayarhvaykta idols in particular. The mystic saints of South India have sung the glory of the arca idols in the ancient Vaishnava temples in their Tamil hymns portraying their direct experience of God. About 106 religious centres have been referred to by them and these have been regarded as holy places by the Vaishnavas.

The quality of easy accessibility (saulabhya) of God in arca form has been the main source of inspiration for the Alvars and the Vaishnava acharyas. God in the arca form is available for worship to all irrespective of the fact whether one is morally meritorious or sinful. Besides, it is believed that the divine enchanting beauty and glory exhibited in the image which can be felt by the ardent devotee transform the minds of human beings and elevates them to a higher spiritual plane. More than this, as the Smriti texts assert, the very sight of an arca murti removes all the sins and thereby makes the persons mentally purer and spiritually richer. The arca vigraha is regarded as subhasraya. Asraya means the support and subha stands for auspiciousness. The idol is asraya since it serves as a suitable object for dhyana or meditation. It is subha because it can remove the sins of the devotees by virtue of the presence of divinity in it. Another greatness of area is the spirit of tolerance on the part of God. As the Bhagavad Gita states, whatever offerings are made with devotion to Him, small or big, are accepted as most satisfying. God tolerates even the offences committed to Him by the worshippers (sarvasahisnuh).