4 The first reason is linked to the present historic moment in the life of the Church, the celebration of the Second Vatican Council. This momentous event confronts the Church with a weighty proposition: to adapt herself, in a suitable way, to the needs of our day. On the success of this endeavor will depend, for a long time to come, the future of Christ's spouse and the fate of many souls. It is indeed a great moment which God has injected into the life of the Church and the history of the world.
Source: Mense Maio (Vatican.va)