"Because the gospel is endlessly rich, it can handle the burden of being the one “main thing” of a church. First Peter 1:12 and its context indicate that the angels never tire of looking into and exploring the wonders of the gospel. It can be preached from innumerable stories, themes, and principles from all over the Bible.
The gospel is so rich that it can be communicated in a form that fits every situation. It is a singular message, but it is not a simple message"
Tim Keller, Center church