All Buddhas preach emptiness. Why? Because they wish to crush the concrete ideas of the students. If a student even clings to an idea of emptiness, he betrays all Buddhas.
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.
Leaving behind the false, return to the true: make no discriminations between self and others. In contemplation, one's mind should be stable and unmoving, like a wall.
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.
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.
The awareness of mortals falls short. As long as they're attached to appearances, they're unaware that their minds are empty. And by mistakenly clinging to the appearance of things they lose the Way.