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.
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?
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.
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.