But as a foreigner, you can also be trained to read classical texts. If you are both intelligent and diligent, you can understand classical texts better than most of native speakers after several years. But that still won't make you 100% correct when understanding them.
It depends on what you are reading.
Buddhist sutras use standardized vocabulary and rigid grammar structures to emulate the original Sanskrit.
However, native Chinese (and Korean, Japanese and even Vietnamese) authors were not restricted and some wrote in heavy literary Chinese like Daoxuan 道宣 in the Tang Dynasty. Even with vast knowledge of Buddhist terms in Classical Chinese you still need to know the literary references. That takes years and extensive reading of the core classical texts (五經). For example, there are often allusions to Confucian ideas which would be clear as daylight to a reader in the Tang Dynasty, but to modern folks it flies over the head.
If you just want to read sutras in Chinese, that isn't so hard. But if you want to read commentaries by native authors, it can sometimes prove quite hard.