The holiness of God is the inaccessible center of his eternal mystery. What is revealed of it in creation and history, Scripture calls "glory," the radiance of his majesty. In making man in his image and likeness, God "crowned him with glory and honor," but by sinning, man fell "short of the glory of God." From that time on, God was to manifest his holiness by revealing and giving his name, in order to restore man to the image of his Creator.
Source: Catechism of the Catholic Church (Vatican.va)