Catechism number 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.