Pope John XXIII
Mater et Magistra §195
Mater et Magistra: On Christianity and Social Progress
195 It is of the utmost importance that parents exercise their right and obligation toward the younger generation by securing for their children a sound cultural and religious formation. They must also educate them to a deep sense of responsibility in life, especially in such matters as concern the foundation of a family and the procreation and education of children. They must instill in them an unshakable confidence in Divine Providence and a determination to accept the inescapable sacrifices and hardships involved in so noble and important a task as the co-operation with God in the transmitting of human life and the bringing up of children. To the attainment of this end nothing can be more effective than those principles and that supernatural aid which the Church supplies. On this score alone the right of the Church to full liberty in the exercise of her mission must be recognized.
Source: Mater et Magistra (Vatican.va)