Catechism of the Catholic Church §412 — excerpt
But why did God not prevent the first man from sinning? St. Leo the Great responds, "Christ's inexpressible grace gave us blessings better than those the demon's envy had taken away."
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.
Also cites: St. Leo the Great, Sermo 73, 4: PL 54, 396 · St. Thomas Aquinas, STh III, I, 3, ad 3
