Defining the Gospel sounds like it would be a no-brainer. It's often trickier than we expect it to be, though.
We tend to equate "The Gospel" with "Salvation." While salvation is certainly part of the Gospel, it's not the sole aspect. Christ's coming, death, and resurrection brought so much more to the story, that is yet to be finished by the way, than we realize. All it takes is a read through the Old Testament to begin to understand why "the good news" is the really really good news.
The key difference is whether or not we view Jesus as merely our Savior or as our Lord. Even though we use these terms to refer to Him, the position of our hearts makes all the difference in our lives as to whether or not we can experience all the aspects of the Gospel that Jesus intended us to.
