Basically guru yoga can be translated as guru devotion. That is: devotion to your spiritual teacher.
On the most fundamental level this is natural. Of course you will be devoted to the person who guides you along the path, helps you become a happier and more balanced person and so on. Since most spiritual teachers have charisma, devotion to them is in some ways a matter of course.
However, as you read this you are probably conjuring up all kinds of images of guru’s misusing their disciples. The advice given in the Gelugpa tradition of Tibetan Buddhism is very simple: if your teacher behaves in a way that you cannot reconcile with his (or her) role as a spiritual teacher, keep your distance. Treat specific outrageous requests, like giving up all your money to him, as jokes.(*)
Of course the main way to prevent trouble is much simpler: only take on someone as your spiritual teacher if you feel you can trust them.
Summer 2012 I attended Lam Rim teachings on Lama Tsong Khapa’s Short Lam Rim text. During the course of those teachings he gave clear instructions on the levels of Guru Yoga in the Tibetan Buddhist tradition. Since these levels make sense in a general Buddhist setting I think it’s useful to share them here.
- When you take refuge or pratimoksa vows, like the lay vows, the teacher who gives you those vows becomes a guru for you on a very basic level. You’re only required to see him or her as a teacher, nothing more. This makes sense as those vows are common to all of Buddhism, including Theravada Buddhism. Since guru yoga plays no part in Theravada Buddhism it would be a break with tradition if it were necessary to see the vow preceptor as a guru in a higher sense.
- When you take the Bodhisattva vows, you are expected to see the person who gives them to you as an emanation of the Buddha. This is still doable, because faults and mistakes come with the territory of emanations of the Buddha.
- When you take a tantric initiation, you are required to see the person who gives those vows as an actual Buddha. Any limitations you see in them will have to be seen as necessary for the development of the students.
- Don’t move too quickly. Some people who pose as spiritual teachers do misuse their position in all the ways that people in power tend to do. It’s better not to have a spiritual teacher at all than to have to break the relationship.
- Keep as much distance as you need in order to be able to see that person as a Buddha. Seeing them brush their teeth may not be conducive to the relationship.
(*) My own teacher, Geshe Sonam Gyaltsen, literally gave the advice to treat outrageous requests as jokes. I’ve heard several other teachers in the FPMT advise to just stay away from a teacher whose behavior you can no longer live with up close. Most of this post is condensed from my notes on the summer 2012 Lam Rim teachings he gave on the short Lam Rim by Lama Tsong Khapa, using the 3rd Dalai Lama’s Essence of Refined Gold and Trijang Rinpoche’s Lam Rim outlines. I did not check these notes against the audio files, nor did I check with the translator to see if I understood everything correctly. Mistakes are entirely my own responsibility.