37 The same conditions which prevailed in the early days of the Church are still to be found in many areas which have been evangelized by missionaries; or at least their peoples suffer disadvantages which had to be left to a future generation to face and remedy. For that reason it is imperative that the laity should in great numbers enter the serried ranks of Catholic action, and thus cooperate generously, earnestly and diligently with the Hierarchy in promoting the apostolate. The work of catechists is assuredly necessary and we wish to give them due praise; yet no less necessary is the industry and skill of those who out of pure charity are ready to help gratuitously the ministers of God in the performance of their duties.
Source: Evangelii Praecones (Vatican.va)