Pope John XXIII
Mater et Magistra §233
Mater et Magistra: On Christianity and Social Progress
233 The Lay Apostolate, therefore, has an important role to play in social education—especially those associations and organizations which have as their specific objective the christianization of contemporary society. The members of these associations, besides profiting personally from their own day to day experience in this field, can also help in the social education of the rising generation by giving it the benefit of the experience they have gained.
Source: Mater et Magistra (Vatican.va)