Catechism of the Catholic Church §57 — excerpt
This state of division into many nations, each entrusted by divine providence to the guardianship of angels, is at once cosmic, social and religious. It is intended to limit the pride of fallen humanity united only in its perverse ambition to forge its own unity as at Babel.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.