Catechism of the Catholic Church §1265 — excerpt
Baptism not only purifies from all sins, but also makes the neophyte "a new creature," an adopted son of God, who has become a "partaker of the divine nature," member of Christ and coheir with him, and a temple of the Holy Spirit.
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.