Once upon a time, there was a bad group of people called Nazis who ruled Germany. They believed that certain people were better than others because of the way they looked or where they came from. They also didn't like some religions, like Judaism, and wanted to get rid of them.
The Nazi leader, Adolf Hitler, wanted to create a new religion, where people would worship him instead of God. He wanted all Germans to be the same religion and follow the same rules, so he made it mandatory to be a part of a church called the German Christian Church. This church said that Jesus was not Jewish and that they could not follow the Old Testament because it was Jewish.
But some Christians didn't agree with Hitler or the German Christian Church, and they kept going to their own churches. They were called the Confessing Church, and they believed in the real meaning of Christianity, even if it meant disobeying the government.
Many Jews, Roma, and other people who were different from the Nazis were sent to concentration camps and killed, and their religions were destroyed. The Nazis used religion as a tool to control people and justify their actions, but it wasn't true religion. True religion is about love, kindness, and treating everyone equally, no matter where they come from or what they believe.