The elimination of religion is something that many governments have pursued. So far, none have succeeded, at least not definitively. For over 2,000 years the Catholic Church has been repeatedly and viciously persecuted and outlawed, but it is still here.
Why do various political systems want to eliminate religion? In Marxist theory, it is necessary to substitute the state as the alpha and omega of people’s lives. Otherwise, the Church is a rival for control, money, and citizen loyalty.
Christianity teaches behaviors that undermine certain political structures, especially dictatorships. For example, how could Hitler or Stalin succeed with a fear-based tyranny if Catholics/Christians are taught to fear only the evil works of Satan?
How could they impose absolute obedience to the state if Catholics/Christians learn to obey God above all else? Those who base their system on racial hatred cannot thrive if Catholics/Christians teach love. Obviously, God and Christian values must disappear.
Money, education, power and property
There are also issues of money and power. Dictators don’t want to share. For them, it is a waste that the tithes go to the church, or that the money is spent on building churches and charities, when all these revenues could go to the state.
Another reason is education. Dictators know that it is easier to deceive an uneducated population, so the first to be executed or exiled are the intelligentsia. Since Catholics are known to build schools wherever they go, the Church must be eliminated.
Although the Church is not intended to be a power structure, there is no denying that an organization representing 1.34 billion people carries weight. Many government officials have resented having to deal with a bishop, especially one who voices opposition.
Remember Henry II of England, who shouted, “Will no one rid me of this troublesome priest?” This outburst led to the murder of Thomas Becket, Archbishop of Canterbury, who had argued with the king over rights to the crown and the church.
Then there are all those church properties. Many dictators seized Catholic property and reallocated it for state use or benefit.
Religious conflicts, atheist governments, gangs and cartels
Until modern times, most anti-Catholic actions were based on conflicts with other religions, i.e. Muslims during the Crusades, Protestants after the Reformation, and once the exploration of the world began, indigenous religions rejecting missionary evangelism.
Then came democracy, a good idea that fits well with Catholic teachings on equality and human dignity. The proliferation of secular governments followed, but so did ideas like fascism and communism with their inherent atheism.
Pius XII played a masterful game of political chess with the Nazis. While secretly helping the Jews, he carefully negotiated to defend the Vatican from invasion and to protect the Church at a time when thousands of priests and nuns were murdered.
From the start, Pius XII knew that the most serious threat to the Church was communism. He was right. As Communism spread throughout the world, people of many nations lost the right to express their faith.
Fortunately, communism largely failed. In former Soviet bloc countries, even in Russia, churches have reopened. Meanwhile, in China, the Catholic Church exists, but under strict control and persecution.
Catholics today face an increasingly dangerous situation in many countries. In some places, like Nigeria and Syria, the problem is once again a question of religion because of Muslim extremists.
In Mexico and Central America, Catholics are terrorized and murdered, especially the clergy. In these cases, cartels and gangs want to silence the Church’s advocacy against violence and corruption.
In the United States, in 15 months of 2020-21, there were 105 incidents of hateful vandalism of Catholic sites, including arson, graffiti and defaced statues.
Persecutions around the world
On its website, Aid to the Church in Need publishes information on the persecution of Catholics around the world. https://www.churchinneed.org/survey-shows-us-catholics-agging-concern-about-global-persecution-of-christians/
For example: In Pakistan in 2020, “1,000 underage girls, mostly Christians, were abducted and threatened with forcible conversion to Islam; in China, mass-goers are subject to digital surveillance; in Nigeria, nearly 3,500 Christians were killed for their faith in 2020, and in North Korea, being a Christian can be punishable by death.
If you search Wikipedia for “Anti-Catholicism,” you get a jaw-droppingly long article. It describes the history of Catholic persecution country by country. https://en.wikipedia.org/wiki/Anti-Catholicism
In 1969, Cardinal Joseph Ratzinger predicted that the Church would experience great upheavals. “She will become small and have to start more or less from the beginning.”
So how small will the Church become? It depends on the number of Catholics who will stand firm, as the Church has done for twenty centuries. Whatever the number, it will always be the Catholic Church, or as the future Pope Benedict said, “a Church of faith”.