PG
This is Kawaguchi Hidetoshi. This is my humble answer to the question.
Honestly, Shakyamuni was not allowed to leave teachings in letters, so it is highly doubtful whether the sutras expressed and handed down in letters to future generations can be taken as true teachings of Shakyamuni if said without fear of misunderstanding, and if anything expressed in letters is not Shakyamuni's teachings, then it is no exaggeration in a sense to say everything “false sutras.”
Why wasn't Shakyamuni allowed to write his teachings...
In my humble opinion, I think it's because there is such a thing as “transcription → fixation of concepts → perception of reality → obsession → hesitation and suffering.”
Also, even if you conceptualize the denial of transcribing as “outrageous,” “far-fetched,” “far-fetched theory,” “far-fetched theory,” the same thing could happen, and after all, it would be inappropriate.
However, when it comes to how exactly we should study and practice Buddhism with the teachings of Shakyamuni, there is no way for us to learn and practice those teachings other than relying on the sutras.
Of course, the scriptures are not unfounded teachings. It can be thought that there is a convenient position in each sutra, such as being one aspect of the myriad teachings of Shakyamuni, which is said to be 84,000, summarized or promised.
Master Asanga uses the term “the purest Dharma equivalent flow” in “The Theory of Regent Dharma,” but I believe that it is necessary to carefully examine and handle the contents of the sutras, assuming that it is a teaching flowing out of the pure world of truth.
The problem is, then, it is necessary to carefully determine which sutras and the teachings in them can or should be relied upon (for oneself and each sentient being). Regarding this, I hope you can also refer to the humble answer below.
Question “Types of sutras”
http://goo.gl/jMyf57
Question “Dragon Tree and Consciousness”
http://goo.gl/GnWUpc
Kawaguchi Hidetoshi Gassho