When you enter into spiritual kingdom, you have to dismantle your material combination of this body. I think it is described in the Second Canto of Śrīmad-Bhāgavatam, how one has to dismantle. That is nirvāṇa. That is called nirvāṇa philosophy. And Śaṅkara gives his spiritual hint, therefore ahaṁ brahmāsmi (Bṛhad-āraṇyaka Upaniṣad 1.4.10). That is also Buddhist version: "Yes, I am spirit soul," but spirit soul, simply their understanding.
Just like a patient. A patient suffering from disease; there are symptoms of disease. Now the symptoms are just fever. Fever . . . if no longer there is fever, doctor says, "Now your fever is now gone," but that is not final cure. There is no fever—that is not final cure. There may be relapse again. There may be relapse again. The final cure is when one is not only out of fever, but he is acting like a healthy man. Otherwise it is again there is possibility of . . . why again?
Suppose there is no fever, but he is lying down on the bed; he cannot do, act, anything, simply sleeping. So that is not cure. He must get up and become active. That is similarly in the spiritual life. Simply to understand that aham brahmāsmi—simply I have realized that I am Brahma, not this matter—that is not cure. You must engage yourself in Brahma activities.
That Brahma activities are this, as you are executing: always engage in Kṛṣṇa's service. That is Brahma activities. That is not ordinary activity.
- brahma-bhūtaḥ prasannātmā
- na śocati na kāṅkṣati
- samaḥ sarveṣu bhūteṣu
- mad-bhaktiṁ labhate parām
- (BG 18.54)
Then one has actually becomes brahma-bhūtaḥ. The symptom is that he does not care any more for worldly pleasures and fame. That is brahma-bhūtaḥ stage, first class. If I have become brahma-bhūtaḥ and again I see, "Oh, my countrymen are suffering. I must open some hospital. They are uneducated. I must open some schools . . ." Why? If you have become brahma-bhūtaḥ . . . na śocati na kāṅkṣati—where is that symptom? You are still lamenting. Na śocati na kāṅkṣati, that is the symptom.