Question: Why do some who pray to Buddha faithfully, who are even vegetarian for many years die of incurable sicknesses?
Answer: Life is already a fatal disease for every unenlightened human, whether vegetarian or not, Buddhist or not. It has never been the case that all Buddhists will not get sick or die. In fact, in the Buddha’s time, there were only a few disciples who never got sick in their entire long lives. (One of them was Ananda, the Buddha’s personal attendant.) This was due to their very strong compassion and positive karma, as partially created in their lives then, and partially accumulated from their previous lives. Being able to depart not due to sickness (but of old age naturally) likewise requires much positive karma. Also, although many in the Buddha’s time attained liberation from the cycle of birth and death, many others who encountered the Buddha’s teachings did not straightaway transcend death. This is so as they needed more time to master the teachings taught.
We ought to remember that the First Noble Truth taught by the Buddha includes the inevitability of birth, ageing, sickness and death for the unenlightened. We also have ripening negative karma from past lives to deal with. For instance, while some Buddhist vegetarians’ lifespans might not seem particularly longer or healthier than average, they could have lived less and in more sickly ways if they did not turn vegetarian, which does create positive karma to dilute existing negative karma’s effects. The severity of sicknesses and pains involved could be less and better handled than others too. All in all, faith aside, it is statistically true that vegetarians, or better yet, vegans, have longer average lifespans with better health than others. (Note than vegetarians who still consume dairy products still remain susceptible to bone-related diseases, cancer and such.)
Although they are invaluable practices, being Buddhist is not merely about praying to Buddha and not eating animals. Buddhist practice also includes learning the more profound teachings well, for cultivating purer conduct in thought, speech and action with greater compassion and wisdom. Those who truly practise the Buddha’s teachings well can indeed lessen suffering of ageing, sickness and death, even if not yet enlightened. They are able to age more graciously with less physical and mental ailments, and depart peacefully, or even blissfully, as in the case of proficient Pure Land practitioners, even possibly skipping severe ageing, sickness and the usual dying process. Upon reaching Amituofo’s (Amitabha Buddha) Pure Land for further training towards guaranteed enlightenment, even before attaining liberation in terms of enlightenment, they will already be liberated (or ‘cured’) from the suffering of ageing, sickness and death.