If someone is determined to reach enlightenment, what is the most essential method he can practice?
The most essential method, which includes all other methods, is beholding the mind.
But how can one method include all others? The mind is the root from which all things grow. If you can understand the mind, everything else is included. It’s like with a tree. All of its fruit and flowers, its branches and leaves, depend on its root. If you nourish its root, a tree multiplies. If you cut its root, it dies. Those who understand the mind reach enlightenment with minimal effort. Those who don’t understand the mind practice in vain. Everything good and bad comes from your own mind. To find something beyond the mind is impossible.
But how can beholding the mind be called understanding?
When a great bodhisattva delves deeply into perfect wisdom, he realizes …the activity of his mind has two aspects: pure and impure …the pure mind delighting in good deeds, the impure mind thinking of evil. Those who aren’t affected by impurity are sages. They transcend suffering and experience the bliss of nirvana. All others, trapped by the impure mind and entangled by their own karma, are mortals. They drift through the three realms and suffer countless afflictions. And all because their impure mind obscures their real self.
The sutra of the ten stages says, “in the body of mortals is the indestructible Buddha-nature. Like the sun, its light fills endless space. But once veiled by the dark clouds of the five shades, it’s like a light inside a jar, hidden from view.” and the nirvana sutra says, “all mortals have the Buddha-nature. But it’s covered by darkness from which they can’t escape. Our Buddha-nature is awareness: to be aware and to make others aware. To realize awareness is liberation.” everything good has awareness for its root. From this root of awareness grow the tree of all virtues and the fruit of nirvana.