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.
In his letter to the Christians of Colossae, the apostle Paul portrays the gospel as the instrument of all continued growth and spiritual progress, even after s believer's conversion.
"All over the world," he writes, "this gospel is bearing fruit and growing, just as it has been doing among you since the day you heard it and understood God's grace in all its truth" (Col. 1:6).
After meditating on Paul's words, 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.
Martin Luther often employed the phrase simul justus et peccator—"simultaneously justified and sinful." He understood that while he'd already been saved from sin's penalty, he was in daily need of salvation from sin's power. And since the gospel is the "power of God for salvation," he knew that even for the most saintly of saints, the gospel is wholly relevant and vitally necessary. This means heralded ...