It is very difficult to respond to the important questions raised in your letter. Why? It is because your aspirations are lofty while my knowledge is limited and meager. Loftiness and meagerness cannot meet; therefore, my teaching will not be appropriate to your needs!
However, in the True Mark Single Vehicle, the marks of loftiness and meagerness cannot be found. Within this Vehicle, whether the marks are lofty or limited depends on how they are conceived. Loftiness and meagerness always possess in full the nature of the Dharma Realm. Moreover, the meagerness to which I refer encompasses all the dharmas of the Ten Realms.
The Pure Land Patriarch Shan Tao has said:
If you wish to study “meaning,” [understand the Dharma] you should study all dharmas, from the mundane level of the Buddhas. However, if you want to engage in “practice,” you should choose a method compatible with the Truth as well as your own capacities and level and then concentrate on it earnestly. Only then can you reap benefits swiftly. Otherwise, even if you spend many eons, you will not be able to escape Birth and Death.
This being so, there is no better method than to recite the Buddha’s name with a mind of Faith and Vows, seeking rebirth in the Pure Land. If you wish to go deeper, you should carefully peruse the Commentary on the Essential Points of the Amitabha Sutra and other Pure Land sutras and treatises.
Buddhism is an open method within the ten Dharma Realms—everyone should practice it and anyone can practice it. Because they do not fully understand its true nature, some Confucian scholars blindly criticize Buddhism … However, the evil karma resulting from maligning the Dharma pales before the karma of vilifying it with one’s own body! These days, some individuals, mouthing Mahayana teachings, consider themselves awakened to the Way. They say: “I am [intrinsically] a Buddha, why recite the Buddha’s name? Afflictions are Bodhi, what is the need to sever them? Lust, anger and delusion are precepts, concentration and wisdom, why sever lust, anger and delusion?
Their words are lofty as the heavenly clouds, but their actions, upon close examination, are as low as the underworld! Such persons may be considered the enemies of Buddhism. Their evil karma is ten thousand times worse than that of persons who malign Buddhism through mere ignorance of the Dharma. While their efforts in studying the Dharma are not entirely wasted, these can only constitute the seeds of liberation in the future. Their transgressions, on the other hand—the vilification of the Dharma with their bodies—will assuredly result in retribution along the Evil Paths for countless eons to come.
You should study Mahayana sutras and commentaries to ensure that your understanding is broad and complete. As far as cultivation is concerned, you should concentrate on Faith, Vows and recitation of the Buddha’s name.