Dharma is from dhri, meaning to hold together, to sustain.
Sanatana Dharma eternally holds All together.
Sanatana Dharma is experience based rather than
belief based.
'Satyam
vada, Dharmam chara'
Literally
means, Speak the Truth and Practice Dharma.
Ancient
Hindu scriptures emphasize the importance of 'Satya' and 'Dharma'. Satya is the eternal, absolute and unchanging
truth. Dharma is often translated as righteousness, Law or Natural Law.
In the Rigveda, the word appears as an n-stem,
dhárman-,
meaning "something established or firm"
The Upanishads saw dharma as the universal
principle of law, order, harmony, all in all truth, that sprang first from
Brahman.
In the
Brihadaranyaka's own words:
Verily, that which
is Dharma is truth.
In the Mahabharata (12.110.11), Lord Krishna defines
dharma as,
"Dhaaranaad dharma ity aahur dharmena vidhrtaah prajaah,
Yat syaad dhaarana sanyuktam sa dharma iti nishchayah,"
meaning, Dharma upholds both this-worldly and
other-worldly affairs.

The prayer,
“तमसोमा ज्योतिर्गमय” Tamasoma Jyothirgamaya, in the tradition of Sanatana Dharma means
“Lead me from darkness to light”. Darkness symbolizes ajnana or ignorance;
while light symbolizes jnana or knowledge.
The Guru alone is capable of guiding one from the
darkness of ignorance to the light of knowledge. It is due to this fact that
utmost importance is given to the Guru in Sanatana Dharma.
About 1200 years ago, Great saint, Jagadguru Sri Adi Shankaracharya, the great philosopher, in his brief life of 32 years was instrumental in the spread of Advaita Vedanta philosophy of the Upanishads. According to Sringeri Peetam Jagadguru Sri Bharati tirtha Mahaswamiji, Adi Shankaracharya re-established the path through which everyone can experience and become one with divinity.
Video link to the documentary released from Sringeri Peetam, about Jagadguru sri Adi Shankaracharya .
Acknowledgements:
http://www.sringeri.net/2010/05/31/publication/dvd/kalady-the-triumph-of-faith-over-time.htm#watchonline
About 1200 years ago, Great saint, Jagadguru Sri Adi Shankaracharya, the great philosopher, in his brief life of 32 years was instrumental in the spread of Advaita Vedanta philosophy of the Upanishads. According to Sringeri Peetam Jagadguru Sri Bharati tirtha Mahaswamiji, Adi Shankaracharya re-established the path through which everyone can experience and become one with divinity.
Video link to the documentary released from Sringeri Peetam, about Jagadguru sri Adi Shankaracharya .
Acknowledgements:
http://www.sringeri.net/2010/05/31/publication/dvd/kalady-the-triumph-of-faith-over-time.htm#watchonline