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.
Unless you see your nature, you shouldn't go around criticizing the goodness of others. There's no advantage in deceiving yourself. Good and bad are distinct. Cause and effect are clear. But fools don't believe and fall straight into a hell of endless darkness without even knowing it. What keeps them from believing is the heaviness of their karma. They're like blind people who don't believe there's such a thing as light. Even if you explain it to them, they still don't believe, because they're blind. How can they possibly distinguish light?
The true Way is sublime. It can't be expressed in language. Of what use are scriptures? But someone who sees his own nature finds the Way, even if he can't read a word.
If you use your mind to study reality, you won't understand either your mind or reality. If you study reality without using your mind, you'll understand both.
To find Buddha, you have to see your nature. Whoever sees his nature is a Buddha. If you don't see your nature, invoking buddhas, reciting sutras, making offerings, and keeping precepts are all useless. Invoking buddhas results in good karma, reciting sutras results in a good memory, keeping precepts results in good rebirth, and making offerings results in future blessings-but no Buddha.
A buddha is someone who finds freedom in good fortune and bad. Such is his power that karma can't hold him. No matter what kind of karma, a buddha transforms it. Heaven and hell are nothing to him. But the awareness of a mortal is dim compared to that of a buddha, who penetrates everything, inside and out.