If you work piously, then you create next life. Life is continuous. We are simply transmigrating from one body to another. So by our work we are creating the next body. So if you be engaged in devotional service, then you do not create another material body. Karma means by working you create another future. But naiṣkarmya means you work, but don't create another future. Everyone has future, but devotional service means end of all future. That does not mean zero. The śūnyavādīs, the voidists, they also want to make it zero, but it is actually not zero. Zero of these material activities. Kṛṣṇa says, tyaktvā dehaṁ punar janma naiti mām eti so 'rjuna (BG 4.9): "One who has understood about Kṛṣṇa, he, after giving up this body, he does not get another birth."
Birth means material body. There is no birth of the soul. The soul transmigrates from one body to another. That is called birth. Otherwise there is not birth. Na jāyate na mriyate, the soul does not take birth nor dies. If there is no birth, then where is death? The body has got birth, therefore there is death. Anything which takes birth, it has got death. But soul is part and parcel of God; God is eternal, therefore soul is eternal.
Therefore it is said we give up this gross body or subtle body but we do not die. Just like we change our dress—I give up this shirt or dress—but I do not die. Similarly, the soul is changing, accepting another material body. The result of devotional service is that you do not accept another material body, but you remain in your spiritual body. The soul is spirit, the soul has got spiritual body—hands, legs, mouth, everything—otherwise, how this dress is made? Dress is made according to the body. So unless you have got spiritual body, how we have got this material hand?
So by discharging devotional service, you don't create another body. That means you remain in your pure, spiritual body. Otherwise karmaṇā—you have to create another body, either human body, cat's body, dog's body or demigod's body, fish body, tree body, so many—8,400,000 kinds of body. So unless you take to devotional service, you will have to repeat this business of transmigrating from one body to another.
So Nārada Muni compiled these śāstras, tantra. Tantra means expansion. Just like there is notebook. Just like Vedānta-sūtra, the lessons are given in codes. Just like the businessmen, they send code. One word composed of four letters, it has got so many meanings. So those who are using those codes, they can understand, "By this code, this sentence or this paragraph is meant." Similarly, the Vedānta-sūtra is giving Vedic knowledge in codes—athāto brahma jijñāsā, janmādy asya yataḥ (SB 1.1.1), ānandamayo 'bhyāsāt (Vedānta-sūtra 1.1.12)—in this way.
This janmādy asya yataḥ code is explained by the whole Śrīmad-Bhāgavatam, eighteen thousand verses to explain this one code. Similarly, the Vedic knowledge is expanded, or also contracted. So tantra is expansion, because ordinary men cannot understand Vedic knowledge. Just like Mahābhārata, it is in the form of history, but in it is Vedic instruction. Similarly, in this Nārada Pañcarātra made by Devarṣi Nārada, it is also Vedic.
Just like we are writing these books, English translations, giving purports. This is also Vedic, because our basis is on the Vedic knowledge. We don't take so-called scientists' knowledge or philosophers' knowledge. We derive it from the Vedas. Therefore tantra means which expands the Vedic knowledge.