What did Paul mean by the Gospel being a declaration?

In 1 Corinthians 15:1-2, Paul states that he delivers what he received—the Gospel. This underscores that the Gospel is a divine announcement of God's redemptive work through Christ, which is independent of personal experience. Paul aims to clarify that the true essence of the Gospel lies in the historical and objective truths of Christ’s death and resurrection. This declaration assures believers that their faith is based on God's promise and accomplishment rather than their own performance, granting them confidence in their salvation.