Why is the message of the gospel crucial for Christians?

In Luke 9:2, Jesus sends His disciples to preach the kingdom of God, which is inherently connected to the person of Jesus Christ. The gospel is a declaration of who Christ is—His life, death, and resurrection—and His authority as the King. This message of the kingdom requires preachers to focus not just on doctrine but on the glorious person of Christ. His work and personhood, as presented in the gospel, are essential for believers as it leads to repentance and faith. The consequence of true gospel preaching is life; sinners are birthed into the kingdom through the proclamation of Christ.