I once assumed the gospel was simply what non-Christians must believe in order to be saved, while afterward we advance to deeper theological waters. But I’ve come to realize that the gospel isn’t the first step in a stairway of truths, but more like the hub in a wheel of truth. As Tim Keller explains it, the gospel isn’t simply the ABCs of Christianity, but the A-through-Z. In other words, once God rescues sinners, his plan isn’t to steer them beyond the gospel, but to move them more deeply into it . . .
. . . a friend told me that all our problems in life stem from our failure to apply the gospel. This means I can’t really move forward unless I learn more thoroughly the gospel’s content and how to apply it to all of life. Real change does not and cannot come independently of the gospel. God intends his Good News in Christ to mold and shape us at every point and in every way. It increasingly defines the way we think, feel, and live.”
~ Tullian Tchividjian in “The Everyday Gospel” in Leadership Journal.
Read the rest of this pithy but powerful article to understand why the gospel is for believers, too.