He gives them a personal example of this. The writer was personally known to them.
Benjamin Keach was pastor of the Metropolitan Tabernacle in the 17th century for some 38 years. He wrote that he was sentenced by the courts to forfeiture of all his goods more times than he could remember. Yes, he was put in the stocks too, but he suffered the forfeiture of all his goods more times than he could remember. Those were days when people suffered for the faith. He did not give up; he did not reverse out. How much disadvantage are we prepared to take and expect for the sake of doing the right things in the gospel and by Jesus Christ?