Highlights of a post by D.A. Carson at: http://thegospelcoalition.org/blogs/tgc/2012/02/29/if-the-apostle-paul-believed-in-the-historical-adam-must-we/
Carson…offers five reflections on Paul’s understanding of Adam:
1. The necessity of the cross requires a literal Adam (1 Corinthians 15:20-27, 45-49)
[N]ot only must we conclude that Paul himself believed in the historicity of Adam, but that the structure of his argument requires the historicity of Adam. In other words, for Paul Adam is more than an optional extra, a mythological accretion which may be excised without loss. Far from it; Paul so tightly relates the saving cross-work of Christ to the significance of historical Adam that it is difficult to see how one can preserve the former if the latter is jettisoned.
2. Human history has a definitive start (Romans 5:13-14)
Paul’s reference to the time period from Adam to Moses (5:13-14) certainly presupposes a historical figure (i.e. Adam) at the beginning of the period, corresponding to a historical figure at the end of the period (Moses). Moreover, this period in world history is not simply an abstract, bounded, temporal entity—we are not dealing with a “time” in the abstract; rather, this period is portrayed as a time during which (a) the “law” (of Moses) had not yet been given; (b) sin was in the world; and (c) death reigned. This threefold description can only refer to the Old Testament period stretching from the fall of Adam to the giving of the law to Moses; and it treats the period as real history inasmuch as all die within it.
3. One act of disobedience brought sin (Romans 5:12-14)
Not only does Rom. 5:12-14 lay considerable emphasis on the one sin, one trespass, or one act of disobedience which brought ruin to the race; but implicitly the argument depends on the notion that before that one act of disobedience there was no sin in the race. This accords very well with Gen. 1-3; it cannot be made to cohere with any evolutionary perspective which denies the centrality of a fall in space-time history.
4. Adam was a flesh and blood type of Christ (Romans 5:14)
Adam is portrayed as the “type” (tupos, NIV “pattern,” 5:14) of one to come. The relationship between type and antitype in the Scriptures is complex; but Ellis correctly insists that New Testament typology cannot be thought of apart from God’s saving activity in redemptive history, as determined by God’s definite plan of redemption which is moving toward a predetermined goal from a specific point of beginning. As Versteeg comments, “Thus a type always stands at a particular moment in the history of redemption and points away to another (later) moment in the same history. . . . To speak about a type is to speak about the fulfillment of the old dispensation through the new.”
5. Adam’s particular sin makes each person a sinner (Romans 5:15-19)
Adam is not portrayed as the first sinner, of which other sinners are later copies; but as the representative sinner, whose first sin affected the race. This distinction is crucial if the parallel between Adam and Jesus is to be maintained; for Jesus is certainly not portrayed as the first man to perform some definitive righteous act, but as the representative man whose definitive righteous act affects those who are in him. Preserve this parallel between Adam and Christ, and the historicity of Adam cannot simply be pro forma, as far as Paul is concerned.