Without the law of God written upon his heart Adam was unable to obey and quickly fell into sin. As the covenant head of mankind, his action pulled the human race into an adversarial relationship with God. Since that day, human beings have been born with a sin nature. For some reason we tend to think of this in terms of genetics. This is a misleading. The fact is, the sin nature is spiritual and covenantal in character. It has nothing to do with our physical being. Adam, as the covenant or federal head of mankind made a decision on behalf of the human race when he rebelled against God and legally bound his offspring to perpetuate a war against the Creator. At the same time, his covenant relationship with God bound he and his posterity to the stipulations of the covenant. In other words, he and all who are descended from him are bound by the original agreement with God and are therefore required to accept Christ as the Savior, the true Kinsman Redeemer. It is for this failure to undertake the covenant demand that unregenerate man is condemned. Thus, in a sense, the non-Believer is not condemned for his sin; all men sin. Instead the natural man is condemned because he is not willing to have his sins washed away in the manner proscribed by the covenant.
The absence of a genetic element to sin does not lesson it’s covenant reality. To illustrate, consider Nazi Germany: Germany of the 1930’s was thoroughly indoctrinated with national Socialism and to one degree or another, every citizen participated in that national identity. Not all Germans were guilty of Nazi atrocities but all Germans were legally bound by citizenship and therefore responsible even if they were not in full agreement. Unless they were actively working to overthrow the Nazi regime they were part of the problem n ot part of the solution. There is no neutrality.
The critical difference is that in the Adamic family there are no dissenters. All who are descended from Adam and remain in his family are living under the legal and covenantal relationship of rebellion and all perpetuate sin in their own life by willful acts of rebellion against God. Certainly man has free will; as a member of this human race he freely chooses to rebel against God. Certainly the Germans under Nazi rule had free will; they freely chose to embrace the ideology of Nazism to one degree or another. Again, the analogy breaks down in that there are no dissenters in the Human race. Everyone descended from Adam freely chooses to reject God.
Thus in the later administrations of the covenant, man as covenant breaker was placed under the headship/mediation of angels. He was also made dependent upon animals since the death of an animal was accepted as a substitute for man. Man related to God through the mediating work of angels and was not allowed into the inner sanctuary of God apart from the blood of an animal, and then only on rare occasions. His status as a covenant breaker was temporarily countermanded through these rituals until the coming of the final Mediator, the last Adam, the Eternal Son Jesus Christ. However, the adversarial relationship was not concluded until the work of the Eternal Son had been completed. The blood of bulls and rams could not reconcile man and God.