1. Paul preaches that the gospel message he taught, which the Corinthians received and now believe, is that Christ died for our sins, was buried, and was raised from the dead on the third day.
2. He argues that if there is no resurrection of the dead, then Christ has not been raised either and their preaching and faith are in vain.
3. However, Christ has indeed been raised from the dead, as demonstrated by his post-resurrection appearances to the disciples and over 500 others, and this secures the resurrection of all believers.