Catechism of the Catholic Church
2090 When God reveals Himself and calls him, man cannot fully respond to the divine love by his own powers. He must hope that God will give him the capacity to love Him in return and to act in conformity with the commandments of charity. Hope is the confident expectation of divine blessing and the beatific vision of God; it is also the fear of offending God's love and of incurring punishment.
2091 The first commandment is also concerned with sins against hope, namely, despair and presumption:
By despair, man ceases to hope for his personal salvation from God, for help in attaining it or for the forgiveness of his sins. Despair is contrary to God's goodness, to his justice - for the Lord is faithful to his promises - and to his mercy.
2092 There are two kinds of presumption. Either man presumes upon his own capacities, (hoping to be able to save himself without help from on high), or he presumes upon God's almighty power or his mercy (hoping to obtain his forgiveness without conversion and glory without merit).
English Translation of the Cathechism of the Catholic Church for the United States of America © 1997, United States Catholic Conference, Inc.