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.
Externally keep yourself away from all relationships, and internally have no pantings in your heart; when your mind is like unto a straight-standing wall, you may enter into the Path.
But when you first embark on the Path, your awareness won't be focused. You're likely to see all sorts of strange, dreamlike scenes. But you shouldn't doubt that all such scenes come from your own mind and nowhere else.
If you see your nature, you don't need to read sutras or invoke buddhas. Erudition and knowledge are not only useless but also cloud your awareness. Doctrines are only for pointing to the mind. Once you see your mind, why pay attention to doctrines?
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?