1 That which We, by the Apostolic authority, have more than once decreed, that an extraordinary year of Jubilee should be kept throughout the whole Christian world, and the treasures of heavenly gifts, the dispensation of which is in Our power, should be thrown open to the faithful-that with the favour of God We have determined to decree for the ensuing year. The advantages of this step will not escape you, Venerable Brethren, who are so familiar with the spirit of the age and the temper of the time, but there is a special reason now which makes Our decision seem more than usually opportune. In view of the fact that in Our recent Encyclical Letter We pointed out how important it is that the States should conform as closely as possible to truth and the Christian ideal, it will easily be understood how fitting it is that We should now use every effort to excite men, or to lead them back to the practice of Christian virtues. For a State is what the lives of the people make it: and just as the excellence of a ship or a house is dependent upon the good quality and the right adjustment of its component parts, so, unless the individual citizens lead good lives, the State cannot keep in the path of virtue, and without offending. Civil government and those things which constitute the public life of a country come into existence and perish by the act of men; and men almost always succeed in stamping the image of their opinions and their lives upon their public institutions. In order therefore that Our teaching may sink into men's minds, and what is the great thing, actually govern their daily lives, an attempt must be made to bring them to think and act like Christians, not less in public than in private.
Source: Quod Auctoritate (Vatican.va)