D&C 45:28-33; Doctrines of Salvation, Smith, 3:259,278; Conference Report, Oct. 1960, pp. 103-105; Book of Mormon Prophecies, Warner, pp. 96-98, 106-108; refer in this text to 3 Ne. 16:10-16
“We are living in the days of the Gentiles when this prediction was to be fulfilled… . If we are living the religion which the Lord has revealed and which we have received, we do not belong to the world. We should have no part in all its foolishness… . If I sometimes, and once in a while I do, go to a football game or a baseball game or some other place of amusement, invariably I will be surrounded by men and women who are puffing on cigarettes or cigars or dirty pipes. It gets very annoying, and I get a little disturbed. I will turn to Sister Smith, and I will say something to her, and she will say, ‘Well, now, you know what you have taught me. You are in their world. This is their world.’ And that sort of brings me back to my senses. Yes, we are in their world, but we do not have to be of it. So, as this is their world we are living in, they prosper, but, my good brethren and sisters, their world is coming to its end.” (Joseph Fielding Smith, Conference Report, Apr. 1952, pp. 27-28)