within this body makes us fearful. But as soon as we purify our existence-we do not even have to come out of our bodies-we will immediately be  abhaya , fearless.
brahma-bhūtaḥ prasannātmā na śocati na kāṅkṣati samaḥ sarveṣu bhūteṣu mad-bhaktiṁ labhate parām Bhagavad-gītā 18.54.
Lord Kṛṣṇa says, "One who is thus transcendentally situated at once realizes the Supreme Brahman and becomes fully joyful. He never laments nor desires to have anything; he is equally disposed to every living entity. In that state he attains pure devotional service unto Me."
We can immediately awaken to our original, spiritual existence, in which there is no more fear, no more lamentation, and no more material desire.
Dr. Singh.  But the scientist would still want some more explanations as to how the living entity can be independent of matter.
Śrīla Prabhupāda.  As long as you are conditioned, you are dependent on matter. For example, a man from Africa is conditioned because he cannot tolerate this cold weather. Therefore he feels discomfort. But there are many people here [gesturing toward children playing on the beach] who are not affected by the cold. The ability to tolerate is simply a question of conditioning.
When you are conditioned, you think in terms of dualities like hot and cold, pain and pleasure. But when you are liberated, you have no such conditioned thoughts. Spiritual life means to become unconditioned-to come to the  brahma-bhūta  stage. That is the perfection of life. Being conditioned means that although the living entity is eternal, due to his conditioning he thinks that he is born, he is dying, he is diseased and he is old. But an unconditioned person is not even old. Kṛṣṇa is described in the  Brahma-saṁhitā  as  advaitam acyutam anādim ananta rūpam ādyaṁ purāṇa-puruṣaṁ nava-yauvanaṁ ca [Bs 5.33] . This means that He is the oldest person, the first person, but that He has no old age. He always appears just like a young man of twenty because He is fully spiritual.