Much of Wayne Grudem's treatment of this topic of sin in chapter twenty-four is legal in nature. In his prayer at the end of Grudem's 2nd and 3rd audio lecture on sin, he confesses that the gravity or consequences was not impressed upon the class as it should those particular days as they should've been. Some space in the text is given to the evilness or perversion or illogicalness of sin. But because Systematic Theology itself is not like a devotional, one cannot expect spiritual exhortation from it. So it may be more understandable to expect legal depictions of sin rather than reasons for sin's emotional weight upon a man. The definition Grudem gives to sin is "Any failure to conform to the moral law of God in act, attitude, or nature." He says any definition that does not include God as the central reason for why sin is so evil does not fully explain sin--right on the money.
On page 495, the author appeals to the doctrine of Imputation to explain Paul's claim in Romans 5 that through or because of Adam's sin, all men were declared guilty. And Grudem is further right to say that if we do away with Adam's imputed sinful nature and say that it cannot be, we must be consistent and say that Christ's imputed righteousness and work on the cross is not ours either. Romans 5 argues both as acts of imputation.
One critique I would like to put forth though, (and I do this hesitantly because Pride is personally my greatest thorn) the cross is not central in this chapter. I don't think Wayne Grudem blows it, because I think he put a lot of time and thought and prayer into this chapter. And it would be sinful to think that somehow he rebelled against God by not putting a large enough emphasis on the weight of sin. Along comes a man like NT Wright and says things like, Martin Luther read his own guilt of sin into the New Testament Text and thats why we have an overblown need for the doctrine of justification. Alarms should be going off. We must be justified because sin is real and God does not take it lightly. The cross is proof of that.
It is in the cross that we are given the greatest legal measurement of sin. It is in the cross that we come face to face with who we are and we meet the Savior of what we have become. We can appraise the price of our sin by what the son of God had to do to propitiate the wrath of God the father. This was no little act. The whole biblical narrative climaxes on this one act. And our sins which we have done, the sin of Adam which we inherit, the sins which we will commit, are dealt with here at the cross. Without an impression of how great our sin is--without a fear of the wrath of a just God, we will be swayed by the words of a man like NT Wright.
Though Grudem does not appeal to the cross in his introduction, he does give a great commentary on the Fall in Garden of Eden, as well as a delicate analysis of the origin of evil. Both are helpful in our formulation of the nature and reason for the imputation of Adam's sin. Later in the chapter, the author discusses babies who die before being born, degrees of sin, Christians who sin and "unconverted Evangelicals", and God's righteousness shown in His punishment of sin.
