Catechism of the Catholic Church

But this "intimate and vital bond of man to God" (GS 19,1) can be forgotten, overlooked, or even explicitly rejected by man. Such attitudes can have different causes: revolt against evil in the world; religious ignorance or indifference; the cares and riches of this world; the scandal of bad example on the part of believers; currents of thought hostile to religion; finally, that attitude of sinful man which makes him hide from God out of fear and flee his call. (2123-2128, 398)