Although the Way of Buddhahood is long and far, ultimately there is not an inch of ground on earth to travel. Although it is cultivated, realized and mastered over a period of three incalculable aeons, the true mind is not remote. Although there may be five hundred miles of dangers and difficult road, the treasure is nearby. If people who study Zen to learn the Way mistake a single step or stir a single thought, they are ten trillion lands and a billion aeons away.
You should simply see your essential nature to attain Buddhahood. The scriptural teachings expounded by the Buddha over the course of his career are instructions for seeing essential nature; when it comes to seeing essential nature itself and awakening to the Way, that is communicated separately outside of doctrine and does not stand on written symbols.
In this there are no distinctions between the sharp and the dull, the rich and the poor, mendicants and lay people, Easterners or Westerners, ancients or moderns. It only depends upon whether or not the will for enlightenment is there, and whether instruction and guidance are mistaken or accurate.
Even if you get directions from a thousand Buddhas and myriad Zen masters, if you yourself do not continue right mindfulness with purity and singleness of faith, you can never see essential nature and awaken to the Way. This is why you realize your own essential nature by means of your own mind and understand your own life by means of your own insight. If right mindfulness is not continuous and concentration is not pure and single minded, your efforts will be in vain.
As long as our concentration is not purely single minded in both activity and stillness, it will be hard to attain even a little accord. Concentration of right mindfulness should be cultivated most especially in the midst of activity. You need not necessarily prefer stillness.
There is a tendency to think that Zen practice will be quicker under conditions of stillness and quiet and that activity is distracting, but the power attained by cultivation in stillness is uncertain when you deal with active situations; it has a cowardly and weakly function. In that case, what do you call empowerment?
Concentration of right mindfulness is a state of absorption that is in oneself twenty-four hours a day, but one does not even know it consciously. Even though you work all day, you do not get tired out, and even if you sit alone or stand silently for a long time, you do not get bored. To search out enlightenment with principle and fact unified is called genuine study.
If you want to quickly attain mastery of all truths and be independent in all events, there is nothing better than concentration in activity. That is why it is said that students of mysticism working on the Way should sit in the midst of the material world.