PIs are Nalandabodhi practitioners who have been students of Buddhism for some time, have completed their ngondro practices and the Study Path curriculum, and have made a strong aspiration to benefit the Nalandabodhi sangha by working with others as a guide to their practice. They have also been trained and approved by Ponlop Rinpoche to do this work.
At Nalandabodhi it is customary for each person to have either a PI, or a Practice "buddy," depending on the situation and level of practice. We encourage one another to practice and to discuss practice with each other. Although PIs are intended for Nalandabodhi members only, non-members can request to have a PI for six months in order to help them determine if they would like to become a member of Nalandabodhi.
The person best suited to advise you on what practice(s) you should be doing is your Practice Instructor. Should further information be necessary, your Practice Instructor will be able to consult with the leadership of the Nalandabodhi Practice Path.
As each sangha member is an individual, no single answer applies in all cases. You and your Practice Instructor should discuss this. Your Practice Instructor will seek further clarification when needed.
For our precious teachers the best protocol is mindfulness, awareness, and respect. Nalandabodhi in general is not particularly "formal" with our teachers, although we do stand when the teacher enters a teaching situation. For visiting Rinpoches, we should follow the protocol that is traditional for them and for the occasion. Specific protocols for Practice Instruction meetings or for audiences with The Dzogchen Ponlop Rinpoche can be found in the PI Manuals. Consult with your PI.
This is to be discussed with your PI, who can further consult with the Nalandabodi Practice Directors.
It is the case that Buddhism does not worship an external deity. However, your "higher power" may be seen as the luminous and clear nature of your own mind, which has never been other than perfectly pure.
You are invited to practice shamatha with Nalandabodhi, to take the Study Path classes and to practice with us during times when we are celebrating the Buddhist holidays. In addition you are welcome to join a "Fresh Heart" class where several shamatha practices are presented and studied. Local centers also often offer additional public meditation classes or open house evenings.
This would be good to discuss with your PI who is familiar with it. If your PI cannot explain the Practice Path of Nalandabodhi, you can consult with the Practice Coordinator of your local center for this information. The path is also laid out in Practice Instructor Manual I.