To reveal this truth, the author of the sutras speaks the following words:
Sutra 19
Because it restores the soul to its original nature, renunciation of materialism brings liberation.
Commentary by Srila Bhaktivinoda Thakura
Misidentification with the material body places the soul in an inauspicious condition, a condition that breeds worthless material desires. By renouncing those material desires, the soul becomes free from the cycle of repeated birth and death. This is so because by that renunciation the soul attains its original nature, which is spiritual and full of bliss. That is the meaning here. This is described in the following words of Taittiriya Upanisad (2.4.1):
"O saintly one, a person who knows spiritual bliss never fears."
In Sandilya's Bhakti-sutra (3.2.93) it is said:
"The soul is both one and different from the Supreme. When he is freed from the material body, the soul is glorious like the sun."
In the Katha Upanisad (1.2.17-18) it is said:
"Taking shelter of the Supreme is the most auspicious activity. Taking shelter of the Supreme is the most auspicious activity. One who takes shelter of the Supreme becomes glorious in the spiritual world.
"For the soul there is never birth nor death. Nor having once been, does he ever cease to be. He is unborn, eternal, ever-existing, undying and primeval. He is not slain when the body is slain."
============ Science of Identity Foundation - Siddhaswarupananda
Those who engage in the culture of nescient activities shall enter into the darkest region of ignorance. Worse still are those engaged in the culture of so-called knowledge.
~Sri Ishopanishad, Mantra 9
Unfortunately, most of humanity spends the majority of its time in the culture of ignorance. We cultivate ignorance by serving our tongue, belly, genitals, and other senses like obedient slaves. The vast majority of our energy goes into this mad pursuit of sense pleasure. Left with frazzled nerves, frustration, anger, jealousy, envy, greed, hate, loneliness, and confusion; we seek an escape in alcohol, cocaine, heroin, and a myriad of other legal and illegal consciousness dimmers. This is the cultivation of ignorance.
============
In the Katha Upanisad (1.2.6), Yamaraja says:
"Fools intoxicated by wealth say this world is all and there is no other. These fools will not be glorious in their next birth. Again and again they will come under my grip."
In the Katha Upanisad (1.2.9) it is also said:
"O dear one, the truth cannot be known by material logic. It is known only by learning it from a self-realised soul. Because you are sincere and determined, you have learned the truth. O dear Naciketa. I pray that my other disciples will be like you."
The words of the sages are our bridge to understand the truth. In the Mahabharata (Bhisma-parva 5.22) it is said:
"Anything transcendental to material nature is called inconceivable, whereas arguments are all mundane. Since mundane arguments cannot touch transcendental subject matters, one should not try to understand transcendental subject matters through mundane arguments."
In Sri Vyasa's Vedanta-suta (2.1.11) it is said:
"Transcendental topics cannot be understood by argument or logic."
In Srimad Bhagavatam (1.2.21), Sri Suta Gosvami explains:
"Thus the knot in the heart is pierced, and all misgiving are cut to pieces. The chain of fruitive actions is terminated when one sees the Self as the master."
Liberation is described in these words of Srimad Bhagavatam (2.10.6):
"Liberation is the permanent situation of the form of the living entity after he gives up the changeable gross and subtle material bodies."
