What is the whole fruition of the Gospel?
It is that Christ was raised from the dead, victorious over sin, hell, death, and everything. The Gospel's bedrock is His resurrection, not merely belief that Jesus was a good man or that He died by crucifixion. That victory is the foundation of the Gospel.
Les explains that after the resurrection, Peter was transformed: he was no longer afraid of Rome, the Jews, or anyone, because he had witnessed the power of resurrection. That resurrection power must be the bedrock of our Gospel. It is not enough to believe Jesus was a good man or that He died a crucifixion; the whole fruition is that He was raised from the dead, victorious over sin, hell, death, and everything. Les notes that in Romans, Paul trumpets this to the world: we are what we are because Christ not only died but rose victorious over our archenemy, breaking the bonds and shackles of sin.