The Flower Adornment Sutra says,

If someone wants to understand
All Buddhas of the three periods of time,
Simply contemplate the nature of the Dharma Realm
Everything is made from the mind alone.

If you put the Buddha's thoughts into action, you're a Buddha. If you practice according to thoughts of a Bodhisattva, you're a Bodhisattva. If you put the thoughts of Those Enlightened to Conditions into practice, you are One Enlightened to Conditions. If you put Hearers' thoughts into practice, you are a Hearer. If you think the way gods do, you're a god. If you have thoughts typical of humans, you're a human being. If you think like asuras, you're an asura. If you have the thinking of an animal, you're simply an animal. If you think the way a hungry ghost thinks, you are a hungry ghost. And if you think the way hell-dwellers do, you are a hell-dweller.

So it is said, "The Ten Dharma Realms are not apart from a single thought of the mind." From this, we can know that absolutely everything is made from the mind alone. There is a verse that discusses the mind quite well:

Three dots like a cluster of stars,
And a hook shaped like a crescent moon;
Furry creatures come from the mind;
All Buddhas arise from it, too.

Look into the verse in detail, and you'll find it describes the mind perfectly. We people here in the world should preserve proper thoughts and not cling to deviant thoughts. What thoughts are considered proper? Thoughts of great kindness, great compassion, sympathy, charity, shame, and remorse are truly proper thoughts. What are considered deviant thoughts? Selfish thoughts, thoughts of benefiting oneself, thoughts of jealousy, hatred, pride, and idle thoughts. Our goal as we cultivate is to get rid of false thoughts while preserving true thoughts. In other words, we want to banish deviant thoughts and foster proper thoughts.

We must preserve a proper attitude in every thing we do. These thoughts are proper knowledge and viewpoints. Don't cling to crooked thoughts, or deviant knowledge and viewpoints. A person with deviant views mixes up right and wrong and doesn't distinguish between black and white. He assumes his actions are correct, and so creates evil karma and falls into the hells without knowing why. Therefore, all the Buddhas spare no pains to warn us over and over: "Don't take the wrong turn in the road. Avoid going down dead-end paths!" They want to tell all of us who cultivate the Way not make bad karma in the Way-place. That is to say,

Don't assume a good deed is too small to do, and fail to do it.
Don't assume an evil deed is too insignificant to matter, and go do it.

We should act with caution at all times and take great care. As we get rid of our bad habits and faults and reform our bad behavior, we should be "as if standing near the edge of a deep abyss; or as if treading on thin ice." We should reform in particular our habit of relying on our excuse-maker: the clever, rationalizing "smart-bugs." Take stock of yourself; see yourself clearly. Don't simply pass the days in confusion, blindly following blind men, cheating each other as you go. This attitude has brought the world to its present state of utter, murky chaos, so it grows more dangerous with each passing moment, leading us inevitably on to doomsday and the extinction of the human race.

People who possess proper thoughts are able to guide the citizens of the world onto proper, broad, well-lit roads. On these right roads, everyone shares similar feelings; everyone helps each other along. It's said, "Helping others is the well-spring of joy." Another adage says, "The greatest joy comes from action done for goodness' sake alone." There are no words to fully describe the happiness that results from a good-hearted resolve to do deeds that are purely good. Only someone who actually does such good deeds knows the flavor of this happiness. Do you want to sample a taste of good deeds? It's truly wonderful, joyful beyond description. By no means should you walk down dark and twisting side roads. Not only can you trip and fall on those crooked paths, but you can easily lead others to the same dead end. Only when your mind is proper, great, and bright can you shine right through all the darkness!