What does the Catechism of the Catholic church say about saints?

The Catholic Church does not canonize someone a saint unless they have displayed heroic virtue and profound faith in their lives. Such example is invaluable, and our recognition of it glorifies God Who wrought such things in the life of the saint. Add to this that saints are heavenly patrons that can aid us should we choose to ask their special intercession. Further, every saint in heaven is the realization of why that soul was created, for every soul is created that it might come to knowledge and choose of its own volition to return to its Creator out of love. For these reasons, every Catholic saint is important for our edification, our assistance, the glorification of God and the realization of God's plan for the human race, to be united with Him in heaven.