What is meant by "pure dharma"? Why is it significant that the Maitreya will teach it?

In China, there have been some prophecies about that there will be a   future saint to bring us the ultimate truth or facts (including all the laws or orders if there is any)， e.g. , .

Since it is the ultimate one, you can imagine it must be so pure that there wouldn't be any mistake.

And  as we all know, China is still at least bit of a communist state. As I  remember there was a famous person (I don't remember who he is ) which  said that when you are young if you don't believe in communism, you are a  bad guy who don't have a good heart, after you've become older, if  you're still believing in communism, you are a fool who don't have a  sound brain.

A communist usually believe that the human being is  able to grab the truth. There is a rumor or legend in china about Karl  Marx that he had grind-ed out a pair of footprints on the floor of a  library which he visited everyday.

At that time there was no sign  of Information explosion，you could still dream of summing up a (pure)  truth from all the books and with that to solve all the problems in the  world.

Now things are different. Maybe people are still dreaming of  a future saint but he has to find an another way. Someone ruining a  small part of a floor of a library haven't brought us a perfect paradise  (pure land). Could we be granted one because somebody of us is sitting  under a tree for a long time?

Hope is always better than fear, let's assume it is possible.

Then  why the present saints and so many ones in the history are not enough,  why we still need a future one such as Maitreya? Why the pure teachings  have become impure?

Should we always blame an outer demon? Is there an inner reason?

By  the way, I'm not a typical Buddhist, in my view, zen may be from   Buddhism (actually The Zhuangzi probably is a more important source of   zen), but far beyond Buddhism.

According to Dajian Huineng, who from my view is the founder of zen,

all  the teachings (including so called pure dharma) can not be the source,  since they have their own source: a sudden awakening. (It is not that the pure dharma is the source of awakenings, but the opposite, the   awakening is the source of all dharma no matter how pure it is.)

If you think we must follow a saint, who is the one that the first saint followed?

People  always overvalue their outer owned things such as a holy book written by a saint, or their own outer behaviors such as eating some particular  food, or their special experiences (no matter spiritual ones or not, no  matter how unique, in my view, they are still the outer instead of the  real inner) .

But can we control a TV set by analyzing the images  (dramas) on the screen? If not, does that mean all the successes of our  logic and the science based on that are a practical joke of "the TV" (it  could be Tao or god or Buddha or some other things e.g. merely  coincidence such as a randomly typing monkey)?
Thus, a good zen  master has nothing to teach you, since all you need to do is just  unbinding yourself from all those clinging. Not only unbinding from the  clinging to the images or phenomena, but also unbinding from the  clinging to all kinds of imaginations and concepts which are related to  "the mirror/TV set/the author", including all the teachings no matter  how pure they are.

They are the blindfolds which are hiding the  ultimate truth including the true nature of ourselves. The salvation is  never from outer things such as a future saint and his holy book which  would be supposed to give us 100% correct (pure) knowledge. The real  salvation is within yourself, since the pure ultimate truth or facts and  the true nature of you( the real you) are the same thing. You have  never divided from it, you can never be an independent one, you (your  body and thoughts and experiences etc ) are always depending on it,  because you and it are the same thing.

What it really is, who you  really are, how should we call them, (usually I call them "the unknown")  would be some everlasting questions and eternal hidden secret. A sudden  awakening wouldn't bring you more knowledge but mere a realization that  all the outer are a kind of dream, the only real thing is yourself,  thus you suddenly wake from the dream. If all you get is a kind of  different dream, and you mistake the new dream as the reality and call  yourself a saint who has more knowledge, more pure facts or truths than  others, you've tricked by the demon. But I'm not talking about an outer  demon. The clinging (or the energy in that grip) and the things cling-ed  (or grabbed) by you are not the same thing. You should release the grip  instead of escaping from the things grabbed by you or cutting off your  hands. (Don't mistake the escaping as a final detachment or an ultimate  liberation.) Who is there grabbing？not your hand, neither an outer  demon.

Thus, the energy or the force is always with you, you don't  need a "may", since the true nature of you is the force, you are the  force.

This is the faith you can get from the sudden awakening. It  is a faith because there is no proof. If you're still searching for a  proof, still need a dream to be made true, still want to be a winner to  prove you're the chosen. It means you don't have the true faith, and it  means you've not awakened, you're still looking forward to a donkey  without knowing that you are riding it. (The reason of that you need to  win a haven or paradise is that you're still fearing the death. It means   you've not realized that there is a birth and death to your hands and   body or to your thoughts and memory, or there is a birth and death to   the state of no thoughts and even no memory, but there is never a birth and death to "the force ".) Although you may understand all the logic in  above words typed by me, if you don't have a faith in yourself, you are  still asking me for a proof or a supporting from some saint or their  "pure" words, it means that you've not actually had that sudden   realization or awakening. You may need another chance. You can look for that chance in all the "pure" teachings of so many saints. Good luck!