In chapter 15, Paul declares the Gospel of Jesus Christ. What is this Gospel? It is the power by which man is saved. The Gospel itself is that Christ died for our sins, according to the Scriptures, and was buried and rose again on the third day. The word Gospel means "good news." What better news could be brought to mankind than that Christ died for the sins of the world, that He conquered death, hell and the grave, and is now seated at the right hand of the Father making intercession for His own?
In this chapter Paul also deals with the resurrection of Christ. We must remember that the Greeks did not believe in the resurrection of the dead. When Paul preached the resurrection at Athens, some of the people actually laughed at him (Acts 17:32).
The Greek philosophers taught that the body was the prison of the soul, and that the sooner the soul was set free in death, the better off the man would be. They looked upon the human body as a source of weakness and wickedness. They could not conceive of wanting to dwell in that body after death. Paul gives several proofs of the resurrection of believers in verses 1-34. He gives historical proof (verses 1-11); personal proof (verses 12-19); doctrinal proof (verses 20-28); and practical proof (verses 29-34).
In verses 35-49 Paul explains the process of the believer's resurrection. He then deals with the second coming of Christ (verses 50-58) and what it means to both the living and the dead. "We shall not all sleep," Paul says. The saints who are alive when Christ returns will be caught up to meet the Lord in the air. "But we shall all be changed, In a moment, in the twinkling of an eye." The Christians who have already died will be called forth out of the grave. This mystery concerns the Rapture of the church. When Christ returns, the dead shall be raised first; the living will then be caught up with them, and all will be changed to be like Christ. Hallelujah what a Saviour!