Catechism of the Catholic Church §1310 — excerpt
To receive Confirmation one must be in a state of grace. One should receive the sacrament of Penance in order to be cleansed for the gift 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.