Okay kiddo, so you know how we have different religions and beliefs? Well, during a time called World War II, a group called the Nazi Party (they were very bad people who did very bad things) didn't like some religions, including the Catholic Church.
The Nazis didn't like the Catholic Church because they thought it was a threat to their power. They wanted everyone to believe what they believed and to follow their rules. They didn't like anyone who disagreed with them or might try to stop them from doing what they wanted.
So, the Nazis started to persecute the Catholic Church in Germany. This means they started treating Catholics badly and doing things to make life harder for them. They did things like shutting down Catholic schools and churches, arresting priests and religious leaders, and even killing some of them.
The Nazis also wanted to control what people read and what they saw in the media. They made sure that nothing was published that criticized their beliefs or their actions. If anyone wrote or said something that the Nazis didn't like, they were punished.
The Catholic Church didn't just sit back and take it though. They resisted the Nazis by speaking out against their actions and trying to protect their members. They also helped Jews and other people who were being targeted by the Nazis.
In the end, the persecution of the Catholic Church in Germany was a very sad time in history. We should always remember what happened and do everything we can to make sure it never happens again.