Catechism of the Catholic Church
1810 Human virtues acquired by education, by deliberate acts and by a perseverance ever-renewed in repeated efforts are purified and elevated by divine grace. With God's help, they forge character and give facility in the practice of the good. The virtuous man is happy to practice them.
1811 It is not easy for man, wounded by sin, to maintain moral balance. Christ's gift of salvation offers us the grace necessary to persevere in the pursuit of the virtues. Everyone should always ask for this grace of light and strength, frequent the sacraments, cooperate with the Holy Spirit, and follow his calls to love what is good and shun evil.
English Translation of the Cathechism of the Catholic Church for the United States of America © 1997, United States Catholic Conference, Inc.