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.
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.
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.
To have a body is to suffer. Does anyone with a body know peace? Those who understand this detach themselves from all that exists and stop imagining or seeking anything. The sutras say, "To seek is to suffer. To seek nothing is bliss." When you seek nothing, you're on the Path.
Whoever realizes that the six senses aren't real, that the five aggregates are fictions, that no such things can be located anywhere in the body, understands the language of Buddhas.
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.
But people of the deepest understanding look within, distracted by nothing. Since a clear mind is the Buddha, they attain the understanding of a Buddha without using the mind.
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.