Pope John XXIII
Mater et Magistra §179
Mater et Magistra: On Christianity and Social Progress
179 Now, in bringing people to Christ, the Church has invariably—both now and in the past—brought them many social and economical advantages. For true Christians cannot help feeling obliged to improve their own temporal institutions and environment. They do all they can to prevent these institutions from doing violence to human dignity. They encourage whatever is conducive to honesty and virtue, and strive to eliminate every obstacle to the attainment of this aim.
Source: Mater et Magistra (Vatican.va)