To enter by reason means to realize the essence through instruction and to believe that all living things share the same true nature, which isn't apparent because it's shrouded by sensation and delusion.
This one life has no form and is empty by nature. If you become attached by any form, you should reject it. If you see an ego, a soul, a birth, or a death, reject them all.
When your mind doesn't stir inside, the world doesn't arise outside. When the world and the mind are both transparent, this is true vision. And such understanding is true understanding.
The Buddha is your real body, your original mind. This mind has no form or characteristics, no cause or effect, no tendons or bones. It's like space. You can't hold it. It's not the mind of materialists or nihilists. If you don't see your own miraculously aware nature, you'll never find a Buddha, even if you break your body into atoms.
Still others commit all sorts of evil deeds, claiming karma doesn't exist. They erroneously maintain that since everything is empty, committing evil isn't wrong. Such persons fall into a hell of endless darkness with no hope of release. Those who are wise hold no such conception.
If you know that everything comes from the mind, don't become attached. Once attached, you're unaware. But once you see your own nature, the entire Canon becomes so much prose. It's thousands of sutras and shastras only amount to a clear mind. Understanding comes in midsentence. What good are doctrines? The ultimate Truth is beyond words. Doctrines are words. They're not the Way. The Way is wordless. Words are illusions. . . . Don't cling to appearances, and you'll break through all barriers. . . .
But this mind isn't somewhere outside the material body of the four elements. Without this mind we can't move. The body has no awareness. Like a plant or a stone, the body has no nature. So how does it move? It's the mind that moves.