[From an Explanation of Chenrezig Puja Session 1, by Bardor Tulku Rinpoche. Translated by Lama Yeshe Gyamtso.]
Who or what is a root guru?
There is a saying about this:
“One may have a hundred gurus who have achieved the bodhisattva levels, but among them there will only be one who changes your mind.”
Every vehicle within Buddhism has a different list of qualifications for what constitutes that vehicle’s version of a guru or spiritual teacher.
We find lists of such qualifications in the Pratimoksha of the Hinayana; in the bodhisattva vow and the other Mahayana contexts; in the tantric, or generic Vajrayana, contexts; and then in the contexts of the Mahamudra and Great Perfection traditions.
But the real point is this: who changed you?
Whose influence, whose instruction, whose kindness actually caused you to change for the better?
Whose influence, whose teachings, caused your relative bodhicitta and your understanding—or realization—of absolute bodhicitta to develop?
Who pointed out the nature of your mind?
And whether or not you have recognized the nature of your mind, the real point is: who has changed you for the better?
If you ask yourself that question, you will know who your root guru is.