The eschatological nature of the Church as theological reflection, it is very relevant, since it is the relationship between the visible structure of the Church and that dream reality as the ultimate goal of ecclesial activity. The eschatological nature of Vatican II brought up this discussion when he emphasized that the eschatological tension between the already and not yet is in the nature of the new people of God, and that, therefore, the Church is sign and instrument of fullness of Hope in the midst of humanity. As a sign, it becomes the world visible sacrament of the unity of mankind with God and with herself. Our research focuses on the position of Vatican II about the situation, the Church s mission, as for the Fathers, the salvation promised by the Lord already begun in Christ, but not yet consummated, because the time of the restoration of all things give will be only when all; the man and with him the whole creation reach its final restoration in Christ. In the meantime the church is compelled to carry on the work of sanctification of humanity as mission charged by Christ in the unity of the Holy Spirit. This work therefore want to show how the salvation of Christ continues through the action of the Church, instructing their children about the meaning of temporal life, as hope of eternal life and commitment to the Kingdom of God.