Catechism of the Catholic Church §618 — excerpt
The cross is the unique sacrifice of Christ, the "one mediator between God and men". But because in his incarnate divine person he has in some way united himself to every man, "the possibility of being made partners, in a way known to God, in the paschal mystery" is offered to all men.
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: GS 22 # 5 · # 2 · St. Rose of Lima: cf. P. Hansen, Vita mirabilis (Louvain, 1668)