Upanishads, the Real Philosophy of Sanatan-Dharma (Hinduism)

    Upanishads, the real philosophy of Sanatan-Dharma
                          (Commonly known as Hinduism)

The Upanishads, known as the Vedanta - the ending or the final, conclusive parts of the Vedas - contain the real essence of Hinduism's spiritual doctrine. They have guided and inspired the greatest minds of India for centuries. 
Bhagavad Geeta - the Celestial Song - is considered the essence of all the Vedas and Upanishads. 

Lately, western thinkers have also discovered the hidden treasures in the Upanishads and Bhagavad Geeta, and are fascinated by the depth of knowledge provided in these scriptures. The basic principles of the universe explained in the Upanishads thousands of years ago, are the same that are recently discovered by modern science - namely quantum physics and the theory of relativity. 

However, the masses - westerns and Indians, Non-Hindus, and even most Hindus derive the understanding of Hinduism - not from the Upanishads but some fanciful books or great epics such as Puranas, Ramayan, and Mahabharat, etc. Although these epics are full of great messages of morality and ethics, they are not the essence of real Hinduism. 

Ordinarily, most Hindus follow the traditional ritualistic way of worshipping that they have seen their parents and others doing for decades. Unfortunately, Non-Hindus - without going into depth - tend to consider that to be the real, authentic Hinduism and miss the real essence of it. 

The Upanishads' approach in explaining the underlying reality of the universe and its creation - nature, and life, etc. - is very systematic and scientific, along with the reasoning.
Before the existence of any so-called monotheistic religions, it was the Vedas who proclaimed:
                    Ekah Brahm, Dviteeya Naastay
There is only One underlying Reality - Absolute Truth - known as Brahm or God - and there is no other (Truth or God).
However, the Rishis, the authors of the Upanishads were very wise, and broadminded as well - with a realistic approach. They understood the human mind - they knew how people tend to think, so they added another phrase:
                             Ekam Satya - Bahudhaa Vadanti Viprah
Although there is only one Reality - one God - but the wise teachers may describe it in many different ways.

Technically, Hinduism is not a religion. It is a geographical identity of the people of Sindhu Valley. The real name of the so-called Hindu Dharma is Sanatan Dharma. The outsiders or the foreigners called it Hinduism - the religion of the people of Sindhu valley. 

The word Sanatan-Dharma means Eternal-Dharma - That which was - is and will always remain - designating it as the Dharma (religion) of One Almighty, Alpervading, Self-Proclaimed God.  
                         
                             'Rajan Sachdeva '