FEAR NOT DEATH,TRUE ESSENCE IS ETERNAL

The Katha Upanishad tells you the story behind life and death. 

Once upon a time in ancient India there lived a pious man named Vajasrawas who had a young and intellectual son named Nachiketa, there comes a day where Vajasrawa decides to do Viswajit sacrifice [one who could give up all transitory things including wealth and all his possessions in order gain knowledge of Brahman / knowledge of reality]. 
 Hence Vajasrawa meets saints to takes advise on him performing Viswajit sacrifice and decides the ceremony date.

On the day of Viswajit sacrifice ceremony Vajasrawa decides to sacrifice few of his least valuable things, observing the ceremony. 

Nachiketa thought, “why is my father sacrificing these old cows which are of no use to anyone and felt that by giving these cows his father would not get the desired result of the sacrifice”.He then obediently asks his father “You are not giving away all your possessions! Dad, Am I not your possession? To whom will you give me Father?”.

At first the Vajasrawa ignored his son but Nachiketa persisted, asking him repeatedly, “To whom will you give me, father? To whom will you give me?”.Vajasrawa angrily replied: “I will give you to YAMA (the God of Death)”.

Those words were unintentional, But Nachiketa decided to obey the words of his father by going to YAMA, Vajasrawa begged his son to stay back, told him his words were unintentional uttered in anger. 

Nachiketa with all his heart had firmly decided to obey his father; head held high with pride told his father, “Our ancestors never slipped on their words and I would love to follow them, my beloved father I want you to follow the same tradition” .

Because Nachiketa knew that one should not fear death, the life on earth is materialistic and unreal the only path which leads to heaven[god] is path made up of truth and peace.

Vajasrawa was deeply moved but with the pride of being father to such a brave son permitted him to follow his decision, with the blessings of his father Nachiketa left to YAMALOKA [Place of Lord YAMA].

On reaching the entrance of Yamaloka, Nachiketa discovered that Lord Yama was not at home, decided to wait at the entrance and waited for three long days on the doorsteps of Yamaloka, The Lord YAMA on his return to Yamaloka saw Nachiketa waiting at the doorsteps and was deeply grieved welcomed Nachiketa to Yamaloka with all due respect. For having kept him waiting for three long days, Lord Yama granted him with three boons.

 First boon: Nachiketa to lord Yama ,“I seek the welfare of my father as my first Boon.” Lord Yama granted him with ease.

Second boon: Nachiketa to lord Yama, “I desire to know how one could reach heaven where there is no sorrow and death” .Yama enlightened him with the details of sacrifices, performances and worships which would lead one to heaven. Yama was delighted with his request, which sounded unselfish and to the betterment of the human race, so thought Nachiketa about all the sacrifices and worship which leads you to Heaven.

As Nachiketa was an intellectual and honest soul spiritually blessed could understand all that was taught hence  Yama named the sacrifice after him.

Third boon: Nachiketa to lord Yama, “When a person dies, there arises this doubt, does he still exists or not. I want you to teach me the truth.” Yama was not expecting this question from a young boy. He tried to divert him but Nachiketa was very firm. He wanted to know the truth.

 Yama was very pleased but he tried to divert the attention with lot of attractive things. Nachiketa declined all these worldly pleasures. Yama was pleased with such a young truth-seeker who had rejected the path of enjoyment and chose the path of goodness. Then Yama taught him the knowledge of the Atman, how humans can attain immortality.

Words of the lord of death: “The Self cannot be known through study of the scriptures, nor through the intellect, nor through hearing learned discourses. The Self can be attained only by those whom the Self chooses. Verily unto them does the Self reveal himself.”  
The Upanishad presents ideas that contrast Hinduism with Buddhism’s assertion that “Soul, Self does not exist”, and Buddhism’s precept that one should seek “Emptiness (Śūnyatā) which is Highest Bliss”  

Know that the Atman is the rider in the chariot,
and the body is the chariot,
Know that the Buddhi (intelligence, ability to reason) is the charioteer,
and Manas (mind) is the reins.

The senses are called the horses,
the objects of the senses are their paths,
Formed out of the union of the Atman, the senses and the mind,
him they call the “enjoyer”.

— Katha Upanishad, 1.3.3-1.3.4

In final verses, the Katha Upanishad asserts that Atman-knowledge, or Self-realization, is not attained by instruction, not arguments nor reasoning from scriptures. It is comprehended by oneself through meditation and introspection. It is not attained by those who do not abstain from misconduct, not those who are restless nor composed, not those whose mind is not calm and tranquil, but only those who live ethically, are composed, tranquil, internally peaceful, search within and examine their own nature.
 Yama,the lord of death, as the spokesman of the Katha Upanishad asserts that man must not fear anyone, anything, not even death, because the true essence of man, his Atman is neither born nor dies, he is eternal, he is Brahman.

Katha in Sanskrit means sorrow.