I must pause to note here that, if we discard the Genesis account and write it off as allegory or in any way as fictitious, Paul’s entire argument falls to pieces.  The whole biblical concept of federal headship, or original sin, and of imputation, is destroyed, if Adam was not literally the first man, and did not literally sin, as is described in the first pages of Genesis.  This is why the Christian church must utterly reject evolution, and any other theory or idea that would write off the account of the creation and the fall as incompatible with human science.  Our faith stands or falls according to the veracity of the Genesis account.  If it is false, there was no Adam, no original sin, no transmission of guilt; and thus also, we must conclude that there is no transmission of righteousness by another federal head, and thus the entire Gospel scheme collapses if we allow that Genesis is a myth.  We must then cling tenaciously to Genesis as much as to John or Romans, else we lose everything upon which our faith is pinned.