b. Original Sin
Chapter 1, “Definition of Original Sin”
Pieper points out that original sin, that which humans have had since the Fall, includes both guilt for Adam’s sin and a corruption of nature. This doctrine of original sin is found objectionable by many, yet Pieper documents it clearly in Scripture. The ultimate outcome of denying original sin, says Pieper (Loc. 11423), is that we must also reject Christ’s imputation of righteousness.
Chapter 2, “The Effect of Hereditary Corruption on the Mind and Will of Man”
Although after the Fall people still have intelligence, they are not, by nature, able to understand spiritual matters. The Gospel is foolishness. We also find our will is not able to change and is only able to oppose God apart from the work of the Gospel. Pieper again gives detailed biblical arguments to illustrate his conclusions.
Chapter 3, “The Negative and the Positive Side of Original Corruption”
This chapter title could easily be misunderstood. By “negative” Pieper means that we are lacking in good. By “positive” Pieper means we actually do things which are bad. Pieper is clear that human nature in itself can be good. It is not human nature to sin, but sin is consistent with the fallen nature. Yet he is clear that we sin on purpose, not by accident only, and that our fallen nature requires it.
Chapter 4, “The Subject of Hereditary Corruption”
The only human who is not corrupt by nature is the Christ. This is because of his conception. Being conceived by the Holy Spirit took away his inherited fallen nature. Pieper is clear that this is due to the Holy Spirit, not due to Mary. Pieper asks where that corruption is. His conclusion is that the curse of sin extends both to body and soul.
Chapter 5, “The Effects of Original Corruption”
Pieper reviews prior segments which indicate the spiritual and temporal death as a result of sin. He asks why eating the fruit would bring death. The conclusion is that the forbidden fruit was deadly because it was forbidden. It was not forbidden because it was deadly. Original righteousness was retained in the setting where the humans would trust God’s word. After the fall, man is no longer naturally able to trust. As a result, we also engage in sinful acts, based on our own desires.