Letting go is a recurrent theme of many spiritual traditions. In this clip from his Burning Man interview, Peter Russell reframes letting go as "letting in" and "letting be".
Samsara means "to wander on endlessly". Peter Russell discusses how we wandering on through life seeking one transient satisfaction after another, not realizing that that which we seek is our true nature. Nirvana means "to extinguish" as in blowing out a flame. Knowing our true nature blows out the flame of desire that drives the endless wandering on.
Samsara and Nirvana
Entheogen means "generating god within". Ayahuasca may well produce profound spiritual openings and personal transformation, but does it really generate a connection with the Divine? From a talk by Peter Russell at Institute of Noetic Sciences
Ayahuasca: Is It Really an Entheogen