Not thinking about anything is zen. Once you know this, walking, standing, sitting, or lying down, everything you do is zen. To know that the mind is empty is to see the buddha.... Using the mind to reality is delusion. Not using the mind to look for reality is awareness. Freeing oneself from words is liberation.
Don't hate life and death or love life and death. Keep your every thought free of delusion, and in life you'll witness the beginning of nirvana, and in death you'll experience the assurance of no rebirth.
To see nothing is to perceive the Way, and to understand nothing is to know the Dharma, because seeing is neither seeing nor not seeing, and because understanding is neither understanding nor not understanding.
The Way is basically perfect. It doesn't require perfecting. The Way has no form or sound. It's subtle and hard to perceive. It's like when you drink water: you know how hot or cold it is, but you can't tell others.
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.