Volume IV examines two Council documents. Apostolicam Actuositatem, or Decree on the Apostolate of the Laity, focuses on the nature and role of lay service in the life of the Church. What is the Church's mission? How is man's relationship with God expressed and lived out in his relationship with the Church? How can the laity participate most effectively in the mission of the Church? Ad Gentes, or Decree on the Mission Activity of the Church focuses on the unique character and requirement of the Church's missionary activity.