In February 2008, I began a blog series called"Gospel Definitions", in which I posted (without comment) any and every definition of "the gospel" that I came across in books or online. Eventually, that series became the largest group of gospel definitions on the web. (See a full list or pdf here.)
As I have posted various definitions of "the gospel" on my blog, I have noticed that people hear the question "what is the gospel?" in different ways.
Telling the Story for an Individual
Some hear this question and immediately think about how to present the gospel to an unbeliever. Their presentation systematizes the biblical teaching of our sin and Christ's provision. They usually begin with God as a holy and righteous judge. Then we hear about man's desperate plight apart from God and how our sinfulness deserves his wrath. But the good news is that Christ has come to live an obedient life and die in our place. We are then called to repent of our sins and trust in Christ. (Greg Gilbert takes this approach in his helpful book, What Is the Gospel?.)
Telling the Story of Jesus
Others hear "What is the gospel?" and think of how the New Testament authors would define the word, which leads to definitions that zero in on the announcement of Jesus. They focus on Jesus' life, death, and resurrection. The gospel, according to this second group, is telling people who Jesus is and what he has done. (Martin Luther, Graeme Goldsworthy, and John Piper take this approach.)
Telling the Story of New Creation
Still others hear the word "gospel" and think of the whole good news of Christianity, how God has acted in Christ to bring redemption to a fallen world. They focus on the grand sweep of the Bible's storyline and how Jesus comes to reverse the curse and make all things new. (Tullian Tchividjian, Tim Keller, andJim Belcher take this approach.)