So the Heart Sutra is one of the most popular sutra in Mahayana Buddhism, said to be the summary and heart of the Prajna Paramita Sutra. It was popularized by the famous monk Xuanzang. It was said that he chanted this sutra when he was lost in the Taklamakan Desert on the way from China to India.
Apart from its terse nature and convenience for chanting. Why is this Heart Sutra so important to Mahayana Buddhism?
Some people even describe the sutra as a kind of 'crazy wisdom' that seems to intentionally tear down all purposeful cultivation.
http://www.lionsroar.com/the-heart-sutra-will-change-you-forever/
It was even jokingly described as the 'heart attack' sutra.
"Also, there is no truth of suffering, of the cause of suffering, of the cessation of suffering or of the path. There is no wisdom, and there is no attainment whatsoever"
Why would this sutra be helpful or useful - when it basically denies the fundamental teachings of the Buddha on the Four Noble Truth?
Presumably the message of the Heart Sutra was so troubling that Thich Nhat Hanh had to 're-translate' the sutra into something that fit in with his own conception of Buddhism:
http://plumvillage.org/news/thich-nhat-hanh-new-heart-sutra-translation/
What is the purpose of this sutra? Is it just sheerly for the shock factor? Maybe like a Zen Master whacking a student with a stick? I find other Prajna Paramita sutras such as the Diamond Sutra just as troubling.
Note: I do enjoy some of the messages of Mahayana Sutras such as Amitabha Sutra and Universal Gate Chapter of the Lotus Sutra and is from a Chinese Mahayana Chan organization.