Right now I’m most interested in verse 12, since I have a friend counseling two friends who are struggling with their faith. I see verse 13 as the preventative medicine to keep away the problems of verse 12. I wonder what “exhort one another every day” actually means. In a family living together I could see this being straight forward. In today’s church, people often live far from each other and the local church making it harder to have meaningful interaction daily, but I suspect the author is intending more than just the pastor emailing everyone a Bible verse of the day.