The Heart Essence and the Orally Transmitted Secrets
The cultivation of Tantric Buddhism is divided into the Generation Stage and the Completion Stage. These stages are very defined in their progressive steps. In Tantric Buddhism, we must receive empowerment and cultivate according to the respective stages. Otherwise, it would be dangerous. This is because, as one gains greater attainment in Tantrayana, greater dangers are involved.
I feel that the Tantric practitioner should begin with the practice of purifying one`s body, speech and mind. Following which, one should cultivate the winds, channels and drops. And through the stages of cultivation, one approaches the Highest Yoga Tantra and finally enters into the Great Perfection.
The detailed division of the stages includes: The Four Preliminaries, Guru Yoga, Deity Yoga, Treasure Vase Breathing Practice, Inner Fire Yoga, Yoga of Drops, Yoga of Non-leakage, the Approach to opening the Five Chakras of Channel Wheels, Vajra Deity Practice, Highest Yoga Tantra, and The Great Perfection.
One may cultivate the sadhanas or methods of Tantric Buddhism following the practice texts, but their deepest heart essence and orally transmitted secrets are never revealed in the practice texts. They must be transmitted orally through the Guru to the initiate, and the doctrines are unknown to the uninitiated. Thus, a sutra states, `The secrets of all Tantric practices must be transmitted personally by the Guru, or there can be no attainment.`
How does one regulate the descent, elevation, retention and dispersion of drops? Without the orally transmitted secrets of the Guru, there can be no progress. Like in the technique of `elevating the drops and leaping over Mt. Sumeru`, the Guru must demonstrate the yoga postures personally. And so must the other techniques be transmitted.
If a practitioner disregards the heart essence and secret keys of the Guru, he or she will have no idea what the keys are, and would not know how to progress. How can he or she achieve yogic response and results? Like a blind man walking along the verge of a cliff, it spells only danger.