The Vedas were passed on orally from teacher to student, and were not written down, and this helped transmit the Vedas without errors. Thus the oral tradition helped preserve the Vedas. And this oral tradition continued for thousands of years, said M.A. Venkatakrishnan, in a discourse.
The Vedas are full of imperatives and orders, with many instructions on what we should follow in life and what we should shun. The Vedas exhort us to always speak the truth; they tell us to live a righteous life; we are told to honour our parents as gods; we are urged to treat guests with the same respect we would show to gods; we are told to treat our teachers reverently as gods. Do not move away from the path of dharma, say the Vedas. Do not keep from studying and teaching the Vedas; whatever your duties, perform them; whatever should not be done, keep away from it — these are rules the Vedas lay down. Thus we have a manual to follow in life, with guidelines clearly laid down.
As for the practical implementation of Vedic orders, we have ample evidence of this in our Itihasas — Ramayana and Mahabharata. Rama obeyed his father’s order, unquestioningly, both with regard to the coronation and with regard to His exile. Lakshmana was the devoted brother who served Rama, without expecting anything in return. Ravana swerved from the right path, and coveted Sita and was therefore killed by Rama. Vali behaved unjustly with his brother Sugriva, and was also, therefore, killed by Rama. In the Mahabharata, the Kauravas were punished for their unjust acts. The Pandavas stood on the side of dharma and were rewarded