13 We feel assured, Venerable Brethren, that all those who glory in the name of Catholic, meditating these considerations, and inflamed by your exhortations, will not fail in this work of piety which We have so much at heart. Nor will they allow their care for the enlargement of the kingdom of Jesus Christ to be surpassed by the alacrity and industry of those who strive to propagate the dominion of the prince of darkness. In the meanwhile, praying God to be propitious to the pious undertakings of Christian nations, We impart most lovingly in the Lord the Apostolic benediction, as a special pledge of Our good will, to you, Venerable Brethren, to the clergy, and the people committed to your watchful care.
Source: Sancta Dei Civitas (Vatican.va)