Although human sin is obvious, we must not forget the form of his art--the great and respectable qualities that are revealed in terms of science, the pursuit of truth, and the concept of the creation and justice of beauty. Whenever we say When we use the words humanity or humanity, we touch a "big mystery"; if we are unaware of this "mystery", then we have succumbed to spiritual death. What does "mystery" in the above text mean? ['Humans who possess art, pursue science, truth and justice are sinful.', 'sinful human beings connected with art, science, beauty, and justice.', 'Although human beings have many well-known sins, they still have great and respectable qualities.', 'To forget the spiritual sins of mankind, but not to forget his great and lovely qualities.']