The significance of Hevajra Tantra is immense. It has led to a synthesis of the essence of Buddhist speculation with tantric theory and praxis. The Hevajra Tantra recommends a gradual and progressive assimilation of Buddhist teachings, culminating in the Hevajra Sadhna. The text of the Hevajra Tantra has fused and synthesised the Sila, Samadhi and prajna of early Buddhism with the basics of Mahayana speculation with both insights as well as practice. It states that the disciples are to be first given an injunction for their conduct, and then instructed upon their fundamental moral precepts. Then they are to be instructed on Vaibhasya doctrine and after that the Sutranta doctrine. Following this are the Yogacara doctrine and then the Madhyamika doctrine. After all this is done, the instructions on the practice of the Hevajra doctrine are commenced. By way of this unique synthesis, the text occupies a significant place in Buddhist literature in general.
The text of the Hevajra Tantra, being a specimen of Vajrayanic literature, is a unique testament to the theory and praxis of tantric Buddhism. It sheds much light on the tantric period of Indian religious history. Previous tantric works, as found in the Guhyasamaja, Manjusrimulaklapa and the Sarvatathagatatattvasamgraha have been given a systematic form and elaborated on in the text of the Hevajra Tantra.
Apart from shedding light on past works, the work has also exercised great influence on succeeding tantra in Buddhism and tantric literature in general. The Hevajra Tantra is the most quoted text in the Sanskrit commentaries on Vajrayanic texts. The Advayavajrasamgraha, Sekoddesatika and others borrow liberally from this text. Verses from the text are found also in the Tantric Buddhist songs in old Bengali as well as in Dohas written in Apabhramsa.
In the matter of magical rites and rituals, generation of yoginis and manifestation of deities, the text claims technical proficiency. The greatness of the Hevajra sadhana is borne by the text itself. The text itself states that nothing can be accomplished without the knowledge of the Hevajra Tantra. It states,
`There is no accomplishment attained by following all the Vedas, Siddhantas and traditions of ritual. By following their purifications, there is rebirth in another cycle of existence. Without this knowledge (of Hevajra Tantra) there is no accomplishment possible in this or any other world. The effort of the one who does not know Hevajra is all in vain.`
The Hevajra Tantra is one of the most renowned of Buddhist tantras held in high esteem in Tibet by the Ka-gyu-pas and the Sa-kya-pas. For them it is a fundamental treatise, and the subject of much exegetical enterprise.
A number of famous acharyas and their disciples are also known to have held the Hevajra in high esteem. Maitrpa (also known as Advayavajra) is known to have had a special predilection for this tantra. It was this rite into which the great Kublai Khan of the Mongols was initiated. The yearning of Milarepa to join the congregation, to which his Guru Marpa, the Translator, is supposed to be preaching the Hevajra Tantra, shows the great esteem it enjoyed among acharyas and their disciples.
Thus, it may be said that the Hevajra Tantra occupies a highly respected position in the Vajrayanic literature. It is esteemed as a unique treatise of tantric theory and praxis. Its peerless position is due to the fact that it has been able to synthesis the inspirations of early Buddhism, later Mahayanic speculations, and tantric insights and praxis.
In fact it has been seen that the deities of the Hevajra Mandala are actually nothing else but the dharmas enumerated by the early Theravada school of Buddhism and Sautrantika school of thought. The practice of virtues that these schools upheld is presupposed in the Hevajra Tantra. The Hevajra tantra is a precise and enlightening compilation of various tantric insights and practices that are common to the Vajrayana school of Buddhism in general. Thus the Hevajra Tantra is highly revered as a masterpiece of Vajrayanic literature.