Catechism of the Catholic Church
1813 - The theological virtues are the foundation of Christian moral activity; they animate it and give it its special character. They inform and give life to all the moral virtues. They are infused by God into the souls of the faithful to make them capable of acting as his children and of meriting eternal life. They are the pledge of the presence and action of the Holy Spirit in the faculties of the human being. There are three theological virtues: faith, hope, and charity.77
1814 - Faith is the theological virtue by which we believe in God and believe all that He has said and revealed to us, and that Holy Church proposes for our belief, because He is truth itself. By faith "man freely commits his entire self to God."78 For this reason the believer seeks to know and do God's will. "The righteous shall live by faith." Living faith "work[s] through charity."79
1815 - The gift of faith remains in one who has not sinned against it.80 But "faith apart from works is dead":81 when it is deprived of hope and love, faith does not fully unite the believer to Christ and does not make him a living member of his Body.
1817 - Hope is the theological virtue by which we desire the kingdom of heaven and eternal life as our happiness, placing our trust in Christ's promises and relying not on our own strength, but on the help of the grace of the Holy Spirit. "Let us hold fast the confession of our hope without wavering, for he who promised is faithful."84 "The Holy Spirit . . . he poured out upon us richly through Jesus Christ our Savior, so that we might be justified by his grace and become heirs in hope of eternal life."85
1818 - The virtue of hope responds to the aspiration to happiness which God has placed in the heart of every man; it takes up the hopes that inspire men's activities and purifies them so as to order them to the Kingdom of heaven; it keeps man from discouragement; it sustains him during times of abandonment; it opens up his heart in expectation of eternal beatitude. Buoyed up by hope, he is preserved from selfishness and led to the happiness that flows from charity.
1822 - Charity is the theological virtue by which we love God above all things for his own sake, and our neighbor as ourselves for the love of God.
1823 - Jesus makes charity the new commandment.96 By loving his own "to the end,"97 he makes manifest the Father's love which he receives. By loving one another, the disciples imitate the love of Jesus which they themselves receive. Whence Jesus says: "As the Father has loved me, so have I loved you; abide in my love." And again: "This is my commandment, that you love one another as I have loved you."98
77 Cf. 1 Cor 13:13.
78 DV 5.
79 Rom 1:17; Gal 5:6.
80 Cf. Council of Trent (1547): DS 1545.
81 Jas 2:26.
84 Heb 10:23.
85 Titus 3:6-7.
96 Cf. Jn 13:34.
97 Jn 13:1.
98 Jn 15:9,12.