Often a question arises in our mind that, if the Vedas teach us of One God, why do we have several images as different "gods". Are they one and the same? Do these "gods" just represent people who once lived on this earth in ancient times, very much like us amongst our ancestors and are raised to a high position for prayers? The earliest verses of Rigveda, later Vedantha theories of Vyasa Maharishi and Sankara's Advitha Philosophy teach us of One God as Paramathma who is unmanifest and all the jeevathma or souls of all created beings including humans, animals and plants and all inanimate objects of universe. They are considered as part of this Universal soul of Paramathma or the unmanifest Divine in His manifest form. The concept of Avathara is explained in all the Agamas, Ithihasas and Puranas. As the religious dharma is practiced over the years, some amount of lust and greed occurs among the people with the decline of wisdom and peace, and injustice prevails over righteousness. This is the time, when God, as Creator and Preserver, wishing to ensure the continuance of this Universe, incarnate Himself in various forms through his Yogamaya, without ceasing to be Himself as Paramathma.

Some of the other theories like those of Dvaitha, Pancharathra Agama and the followers of Vaishnava Sampradhaya believe that Paramathma is never Nirguna or unmanifest. He is actually manifest but not comprehensible. Sri Vasudeva or Narayana is the Savisesha Brahman or Iswara who takes the various forms to be understandable for our prayers. Similarly, Saivas according to their Agamas, believe Siva as the Supreme God, as Nirguna Siva in the form of Sat-Chit-Ananda. He created the Universe and is the cause and effect of all beings with all His grace, force and energy. Sakthas worship Sakthi as the Supreme Deity, as the Mother of the universe, who created the world and all the forms of Gods for our worship. They consider Sakthi as the dynamic force of Brahman and the Creative energy or the force behind Siva in His manifestations. Smarthas perform Vedic rituals to 'Devas' and perform prayers to Siva, Sakthi and Vishnu and to their various manifestations as "Ishtadevatha" at home.