What is the plan of salvation regarding death?
Because all have sinned, death is mandated. The plan of salvation provides a loophole: believers need not die in themselves, but can take Christ's death as substitution. By believing the gospel, Christ's death takes their place, and the old Adam is crucified, freeing them from sin.
Les explains that God's first fundamental law in Scripture is that the soul that sins shall surely die, a command repeated in Ezekiel and affirmed by Paul in Romans, where all have sinned and come short of the glory of God. Since Adam sinned and every son of Adam sins, death is the mandated result and there is no getting around it. But God gave mankind a loophole: we have to die, but we do not have to die in ourselves. We can take Christ's death as our substitution. The plan of salvation is that if we simply believe the gospel, Christ's death takes our place—what is called the substitutionary death of Christ. Therefore, Paul teaches that the old Adam has to be crucified and put to death because he is a sinner, and he that is dead is freed from old Adam.