So much of the Zen that people enjoy today, such as koan collections or the records of Zen masters like Yun-men and Chao-chou (J., Joshu), were of especial interest to literati Zennists in T’ang and subsequent dynasties.
Chinese literati, many of whom were government officials, were of an intellectual and literary (poetic) disposition. They had enormous power and, very much, helped to spread Zen Buddhism in China during the T'ang and subsequent dynasties. They were also the recipients of the teachings of Zen masters and recorded much of the history of Zen. These same literati were also steeped in Confucianism and Taoism. They saw Buddhism, Confucianism, and Taoism as being harmonious.
It almost goes without saying, but Zen literature, especially koans, is highly complex, filled with a great deal of imagery and allusion. Literati were very much gifted in, not only the art of writing poetry, but also appreciating its subtleties. The average Westerner who takes up Zen has to be prepared to become a literatus to some degree which will be difficult and take time. As Nietzsche said once, one cannot fly into flying. Before one would learn to fly they must first learn to stand and walk, etc., according to Nietzsche.
Rather than going through koan collection such as the Blue Cliff Records or the Book of Serenity, which were better suited for skilled Chinese literati, I much prefer the Zen sermons or yulu. These sermons include, Red Pine’s, The Teaching of Bodhidharma, Blofeld’s, The Zen Teaching of Huang Po and The Zen Teaching of Hui Hai, and a real gem, Arthur Braverman’s, Mud & Water: The Collected Teachings of Zen Mater Bassui and many others. They are all, more or less, a reflection of the Lankavatara Sutra and The Awakening of Faith treatise, attributed to Asvaghosha.
As far as the discourses of the Buddha are concerned as found in the Pali Nikayas and the Mahayana Sutras they have to be studied. There is no getting around it. This is part of the standing and walking, mentioned earlier, followed by running, climbing and dancing that have to be achieved before we can fly according to Nietzsche.
Beginners are at a terrible disadvantage when they get involved with koan collections like the Mumonkan. The danger here, is that the beginner will take koans in a literal sense, not as allusions to one’s true nature, but rather as ways of behaving. For example, if somebody asks you what is the essence of Zen just say, “Mu.” Koans are really antidotes to the unbridled habit of trying to conceive our true nature which was what the Chinese literati were guilty of and explains why koans were developed. The koan is more like using fire to extinguish fire. In this regard, koans work best when one person is awakened to pure Mind who helps another to awaken. In truth, koans are not necessary. But the study of sermons are of a big help.