The gospel is the fundamental thing we believe as Christians. Below are resources that will help you understand and grow in your knowledge of the gospel:
Books
The Explicit Gospel - Matt Chandler
"Even if you go to church, it doesn’t mean that you are being exposed (or exposing others) to the gospel explicitly. Sure, most people talk about Jesus, and about being good and avoiding bad, but the gospel message simply isn’t there—at least not in its specificity and its fullness.
Inspired by the needs of both the over-churched and the unchurched, and bolstered by the common neglect of the explicit gospel within Christianity, popular pastor Matt Chandler writes this best-selling treatise to remind us what is of first and utmost importance—the gospel."
Gospel Fluency - Jeff Vanderstelt
"Teaching believers what it looks like for the gospel to become a natural part of our everyday conversations, Vanderstelt shows that the good news about Jesus impacts every facet of our lives."