First of all, this sentence is about the boundary between right and wrong. Countless theories simply tell us everything is right and wrong, right and evil, good and evil, no doubt, and there are countless examples to support it. But is there really a right or wrong? Is a person really either right or evil? Does life really have to be divided into good and evil? I don't think so. Life is complicated and full of changes, so life is colorful.
Let's talk about cultivation. I think this sentence means "unity of knowledge and action". There are thousands of reasons recorded in the book, but the ultimate goal of these theories is not to make people stick to the rules, but to be used by people to create happiness for more people. If a person always lives under dogma and nostalgia, his life can be said to be gloomy and boring. Under the guidance of theory, only by exploring, practicing and breaking through all kinds of embarrassment in life can life be truly full of color, and that is the real endless life.