"Religious Socialism, Christian Socialism, are contradictory terms; no one can be at the same time a good Catholic (Christian) and a true Socialist." - Pope Pius XI (1922-1939)
The word "socialism" and "socialist" are often used in discussions today, but "few people in the modern Western world understand what socialism is" ... or the "traditional Marxist view of socialism.” Socialism is not only about caring for the poor and eradicating poverty as many people mistakenly believe. "From Pope Pius IX (1846-1878) to Pope Benedict XVI (2005-2013), the popes have consistently condemned socialism" as "destructive" and "wicked."
"Socialism, like Communism, advances the view of the state as the supreme authority and inevitably persecutes religion.... Even when the persecution is not blatant or heavy-handed, the belief that the state is higher than the Church leads to innumerable forms of persecution. For example, God is not rightly acknowledged in the public forum, prayer is silenced, morality based on God's laws is ridiculed, taxes are used as coercion, and worship can be prohibited for what the government deems as just cause."
Socialism advances class warfare and the deadly sin of envy. Pope Leo XIII (1878-1903) said, "The great mistake is the notion that class is naturally hostile to class and that the wealthy and the working man are intended by nature to live in mutual conflict. So irrational and so false is this view that the direct contrary is the truth ... Each needs the other: capital cannot do without labor, nor labor without capital. Mutual agreement results in the beauty of good order, while perpetual conflict necessarily produces confusion and savage barbarity."
"Too often Christians attracted by Socialism tend to idealize it ... They refuse to recognize the limitations of the historical social movements... Pope Paul VI (1963-1978)
"We make this pronouncement: Whether considered as a doctrine, or an historical fact, or a movement, Socialism, if it remains truly Socialism, ... cannot be reconciled with the teachings of the Catholic Church because its concept of society itself is utterly foreign to Christian truth." -Pope Pius XI (1922-1939)