One of the most remarkable expressions of the all-encompassing nature of the cross is reflected in an incidental, but extremely important, comment that Paul made in his First Letter to the Corinthians. He noted that when he brought “the testimony of God” to Corinth, he hadn’t come “with eloquence or human wisdom”. He instead “resolved to know nothing…except Jesus Christ and him crucified’ (I Cor. 1:1-2).
While this statement may be somewhat hyperbolic (did Paul really resolve to know absolutely nothing except Christ crucified?), it clearly implies that, for Paul, the entire gospel was found in the message of the cross. It implies that, when we understand what took place through the “foolishness of the cross,” we understand all that we need to know about God and about other humans. When you know the character of God revealed on the cross and what he thinks about us, as revealed on the cross, you’ve got the essence of all you need to know about anyone.
Excerpt from Benefit of the Doubt, pages 233-234