What does Les mean when he calls the gospel the finished work of the cross?
The finished work of the cross refers to the completed redemptive work of Christ—His crucifixion, burial, and resurrection, including His shed blood. It is the gospel by which sinners are saved through believing alone, with nothing added, because Christ has done it all and delivers believers from Satan's power.
Les explains that the finished work of the cross is the gospel—the body of truth that Christ was crucified, buried, and rose from the dead, as Paul writes in 1 Corinthians 15:1–4. The shed blood is implied in His death and cannot be left out. Les pictures this work as opening our Red Sea and taking us away from the power of the Egyptian army behind us, or Satan’s power. Salvation is by believing plus nothing, because Christ has done it all.