Philosophy is the rational part of any religious faith and it is an integral Part of Hinduism. It inquires into the nature of the truth or the Supreme reality. It gives clear solutions to most profound and subtle problems of life. It shows the way to get rid of pain and suffering, to get released from the samsaara, the cycle of birth and death, and to reach immortality and eternal bliss. This has been the strongest motivating force and power of religion and religious life. A clear understanding of man's relation to God and to the universe and the meaning on this birth and death is a matter of importance to all aspirants of Hindu Philosophy. Swami Sivananda says that philosophy will take you to the gates of the realm of eternal bliss, but it can not allow you to enter that realm. Intuition or realization is necessary for entering into that holy land of everlasting joy and ineffable glory. Such a philosophical theory based on the mystical experience of the sages and intuitive perception and realization of the eternal truth by the founders has lead to the establishment of the Tenets and Ethics of Hindu religion.

The Dharma Sasthras describe these fundamental rules for mankind and are different for each of the four eras or Yugas. In the Kritha Yuga a person will have to study all the Vedic teachings and do many years of intense meditation to attain liberation and in Thretha Yuga one will be performing many big Homa rituals and follow the Vedic teachings of Upasana to reach the same. In the Dwapara Yuga, prayer services to Deities in various forms of His manifestations were sufficient. In the "Advanced civilization" of modern times of this Kali Yuga, as people are very busy working for their material benefits, worship with a deep Bhakthi or devotion to God and recitation of His name "Smarana" with concentration is enough to get liberation. The ethics and tenets of Hinduism and rules of rituals are based on this Philosophy. Sri Sankara, Sri Ramanuja and Sri Madhva and several other great Acharyas established the traditions of rituals and devotional practice at home. The practice, however, got modified according to the social class, caste, age (ashrama) and the needs of the modern society.

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.