Buddhism is like a supermarket with plenty to offer. The Guhyagarbha Tantra of the Nyingma tradition states that Buddhism can be divided into five vehicles (yanas): Human and Celestial Beings (vehicle of seekers of fortune and bliss in the human and god realm respectively), Sravakayana, Pratyekabuddhayana, Bodhisattvayana, and Vajrayana. Whatever and however one seeks to practice the Dharma, various modes of practice can be found in Buddhism to suit each one’s aspiration. As in a supermarket where one can pick and choose freely, there are different levels of practice in Buddhism, from the worldly to the sublime, up to the incomparable Great Perfection, available for selection at one’s own discretion. Although the wish of the buddhas and bodhisattvas is for everyone to practice for the attainment of liberation instead of worldly benefit, it is only a wish on their part. They will not force everyone to practice Vajrayana, nor Mahayana or Theravada for that matter, because sentient beings differ in their capacity. Is one method sufficient to bring all out of samsara? Apparently not. It is precisely for this reason that the Buddha turned the wheel of Dharma three times, and transmitted eighty-four thousand teachings. There would be no need for all of these if one method alone could work its magic.
~ Depicted from THE GATEWAY TO VAJRAYANA : Vajra Master and Empowerment