All the great teachings of the Tripitaka can be thought of as being expedient tools to help people break their egotistical grasping, the habit of many lifetimes, at material object as well as at the concept of a personal self. Because the potentiality of all sentient beings for spiritual development is very different, the buddha has bestowed on us a wide range of different teachings and methods to fit every individual's need. Depending on the particular illness, a particular medicine can be prescribed. If all sentient beings did not hold any grasping view whatsoever, the Buddha would, in reality, have had no Dharma to speak . However, because the past roots of sentient beings are so very different, thus, also, the expedient teachings of the Tathagata are not uniform. On the other hand, if they are to be used expediently to help everyone, the teachings of all Buddhas are, in reality, just like a finger pointing at the moon. We must never mistake the finger for the moon! These teachings also direct one who is lost, enabling him to find the true and safe way to return home.
The Supreme Dharma is without words and is inconceivable. However, one who is intelligent and ready can enlighten his own mind suddenly by realizing that all corporeal entities are, in reality, no different from the universal "It is just so" or "It is thus" condition of the Absolute. However, the spiritual roots of most sentient beings are quite dull; and, lacking some expedient method, they cannot become liberated from their habitual conditioning and Karma. Therefore, Buddhism has developed the expedients of the Three Vehicles and the Five Different Natures to urge people of all kinds and degrees of development and practice to initiate, nurture and embrace the Bodhi Mind and to protect the Dharma and preserve its stability and integrity. In this light, Buddhism promises that if one becomes enlightened regarding his Real Nature or Original Nature in this present lifetime, then he will attain the fruit of this realization in his next lifetime.
Ch'an Master Ch'an Yuan, out of great compassion, wrote his work Practice and Attain Sudden Enlightenment, using the dialogue format between a monk-student and his master to develop concepts about the nature of the Absolute, Original Mind, Enlightenment, practice, etc., assuming that future student of the Dharma would surely benefit from this design. The world is so structured that each sentence, if read with care and attention and clarity, can reveal one's True Nature; and each word can enlighten one's mind, purifying one's evil or impure thoughts and wiping out one's heterodox views. Ch'an Master Ch'an Yuan points directly to the Wonderful Source of one's True Nature and reminds his reader-students that, whether they use the sudden or the gradual method to become enlightened, when the time is ripe they will attain Bodhi completely and thoroughly and, thereby, become Buddhas suddenly.
This Dharma and the enlightenment achieved by understanding it are like the boat or raft of salvation floating on the ocean of suffering or like the single light piercing the pitch-black night of ignorance to show all sentient beings the True Way.
My most fervent desire is that all of my virtuous friends in the Dharma, as well as all other sentient beings, should clearly comprehend the deep purpose of the Tathagata and understand the mind of the Patriarch, who urges everyone to purify and enlighten his own mind. "Without a single thought arising" is the condition and being of the Perfect and Completely Enlightened One.