62 How many good works some missionary, now hindered in his apostolic labors by poverty, might not accomplish with the money not infrequently squandered on fleeting enjoyment by some thoughtless Christian! It behooves every child of the Church, every family, every group of Christians to examine themselves diligently on this point. Let them reflect on these words: "You know the graciousness of our Lord Jesus Christ - how, being rich, he became poor for your sakes, that by his poverty you might become rich." Then let them set aside some of their superfluities, nay, at times, something of what they need. Remember that in your charity are found the means whereby the boundaries of religion may be broadened; and the face of the earth will be renewed if charity prevails.
Source: Fidei Donum (Vatican.va)