5 Christ's redemptive work, while essentially concerned with the salvation of men, includes also the renewal of the whole temporal order. Hence the mission of the Church is not only to bring the message and grace of Christ to men but also to penetrate and perfect the temporal order with the spirit of the Gospel. In fulfilling this mission of the Church, the Christian laity exercise their apostolate both in the Church and in the world, in both the spiritual and the temporal orders. These orders, although distinct, are so connected in the singular plan of God that He Himself intends to raise up the whole world again in Christ and to make it a new creation, initially on earth and completely on the last day. In both orders the layman, being simultaneously a believer and a citizen, should be continuously led by the same Christian conscience.
Source: Apostolicam Actuositatem (Vatican.va)