# Atheism ## Catechism of the Catholic Church The denial in theory and/or practice that God exists. Atheism is a sin against the virtue of religion required by the first commandment of the law ([[3.2.1.1.p7e|ccc-2124]]-[[3.2.1.1.p7e|ccc-2125]]). ## Vatican II - atheism — "atheism must be accounted among the most serious problems of this age" — [[gaudium-et-spes-01#^gs-19|GS ¶19–21]]