What does Revelation 1:9 mean?

I’m John, your brother and partner in the trouble, the kingdom, and the endurance that come from being with Jesus. I was on the island called Patmos because I was sharing God’s word and the truth about Jesus. Revelation 1:9 - Modern Text Bible

(John is connecting with his readers, saying he’s suffering and persevering just like them, and he’s on Patmos because of his faithfulness to Jesus.)