To attain dvijatva in the true sense, a knower of mantra śāstra needs to accomplish śuddhi of yoni, bīja, āhāra, deśa and bhāva. All of these can be accomplished through the sole agency of mantra. The human body is born of the female essence [rajaḥ] and the male essence (vīrya). In recent times, due to impurity of both these essences, a śuddha deha is not attained at birth. Also, the true purport and technique of accomplishing samskāras such as garbhādhāna is forgotten. Since the coming together of a man and woman is primarily due to lust or kāma, such union cannot result in the birth of a pure body (viśuddha deha).
Thus, a practitioner of mantra śāstra needs to necessarily purify the male and female essences within oneself (yoni and bīja) to attain a state of purity that can facilitate higher states of consciousness. By following various śrauta and smārta diktats in terms of consuming food, a certain level of āhāra śuddhi can be attained. But in today’s age when strict adherence to numerous such rules cannot be followed, one will need to skillfully resort to mantra prayoga to accomplish āhāra śuddhi. By samparka with those not following dharma, deśa becomes aśuddha and emotions such as falsehood, wickedness etc. result in the pollution of bhāva. The fastest and most effective way of achieving deśa and bhāva śuddhi is again through the agency of mantra.
Having thus purified oneself through the mantra, one attains what can be called a second-life in the realm of śuddha-vidyā which is when he can be truly called a dvija. This dvijatva is alaukika – as compared with laukika dvijatva.
After one attains such a rebirth, the first samskāra he undergoes is that of upanayana. The upavīta here is the śakti sūtra which is representative of the realm of śuddha vidyā spanning across infinitude of mantra and devatā varga. All samskāras in this realm of śuddha vidyā pertain to the samskāra of the consciousness rather than of the gross and subtle bodies. Having accomplished such caitanya samskāra, one attains rudrāmśa. Without attaining rudrāmśa, it is indeed difficult to attain īśvara sāmya. Thus, mantra is truly a kalpataru and its importance cannot be sufficiently emphasized.