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?
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.
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.
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.
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.
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.