The less oxygen Zen gets from Buddhism the less Zen becomes. It soon turns into a kind of one dimensional yoga of just sitting. But fundamentally, Zen is not about sitting. It is about awakening to our true nature which is pure and luminous; free of defilements. This is what Buddhism tells us. We have to do more to get to a state of seeing our true nature. Sitting is but a small part.
As I see it, we need to go into a solitary retreat. We have to be alone—really alone—in which our higher self gains power over the lower self in a kind of sublime struggle. When I lived alone without electricity, my nearest neighbor being 7 miles away, the Lankavatara Sutra and others like the Diamond Sutra had more of an impact upon me. Their depth was more apparent. Over time I gained confidence in awakening to pure Mind. I knew this is what I had to do. I couldn’t waste time anymore, setting aside this most important quest.
In this solitary retreat you are in nature’s vital world—not man’s often distorted and needlessly cruel world. Nature becomes active in helping you to achieve your goal of awakening only because you trust that every thing under heaven and earth wishes liberation as you do. Nature sends you many signs. Then eventually you come to your wit’s end, exhausting all your vain attempts at seizing pure mind. Then and only then can you enter the gate.