Catechism of the Catholic Church §1617 — excerpt
The entire Christian life bears the mark of the spousal love of Christ and the Church. Already Baptism, the entry into the People of God, is a nuptial mystery; it is so to speak the nuptial bath which precedes the wedding feast, the Eucharist.
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: DS 1800 · CIC, Can. 1055 # 2