Mater et Magistra §159

¹⁵⁹ The Church has always emphasized that this obligation of helping those who are in misery and want should be felt most strongly by Catholics, in view of the fact that they are members of the Mystical Body of Christ. "In this we have known the charity of God," says St. John, "because he has laid down his life for us; and we ought to lay down our lives for the brethren. He that hath the substance of this world and shall see his brother in need and shall shut up his bowels from him; how doth the charity of God abide in him?" (42)