Svarūpa Dāmodara: The spirit soul must necessarily have a body, either spiritual or material.
Prabhupāda: He has got already spiritual body. Material body is his covering. It is unnatural. Real body is spiritual. Just like your coat, this is unnatural. But your real body is natural. Otherwise how transmigration is possible? I am accepting different unnatural bodies. Unnatural means to my constitution. My real constitutional body is servant of Kṛṣṇa. So, so long I do not come to that position, I remain servant of nature and I get so many bodies. According to the nature's direction I am getting body, I am giving it up, again I am desiring something, I am getting another body. This is going on. Prakṛteḥ kriyamāṇāni guṇaiḥ karmāṇi sarvaśaḥ, ahaṅkāra-vimūḍhātmā (BG 3.27). He is a rascal. He is thinking, "I am this body." Īśvaraḥ sarva-bhūtānāṁ hṛd-deśe 'rjuna tiṣṭhati, bhrāmayan sarva-bhūtāni yantrārūḍhāni māyayā (BG 18.61). This is a yantra, machine. And we are traveling many species of life, all riding on this car, given by nature. Yantrārūḍhāni māyayā. Māyā has given this vehicle, anywhere wandering, up and down, sometimes demigod, sometimes dog. This is going on. And in this wandering process, if he gets in touch with a devotee, then his real spiritual life begins. Otherwise he has to go on, rotating.