Okay kiddo, let's talk about the Great Moscow Synod.
So, you know how churches have important people who make decisions and rules about how the church works? Well, the Great Moscow Synod was a big meeting of important church people in Russia in the early 1900s.
They met to talk about how the Russian Orthodox Church should be run and what rules they should follow. They talked about things like how to teach the Bible, how to worship, and how to help people who are sick or poor.
One of the big things they talked about was a man named Sergei Nilus. He wrote a book that some people thought was very important, but others thought was dangerous and should be banned. The Great Moscow Synod decided to ban the book, but some people were still upset about it.
This meeting was very important for the Russian Orthodox Church because it helped them make important decisions about how to follow God and how to help people. And that's what the Great Moscow Synod was all about.