What does it mean that the gospel is a mystery?

The concept of the gospel as a mystery is made clear in 1 Corinthians 2, explaining that it is hidden from the wise and revealed to those whom God chooses. This mystery refers to the deep truths of Christ's salvation that cannot be grasped by human wisdom or effort. Only through the Spirit can individuals truly understand the gospel's significance. The preacher's obligation is to communicate this mystery clearly, and they must rely on God's revelation for effectiveness in their ministry.