Why did Paul present Adam as the first federal head with Christ as the culmination?
Paul presents Adam as the first federal head of the human race and Christ as the culmination because Scripture follows the rule first the natural, then the spiritual. Adam stands for the physical order, while Christ fulfills the spiritual. This contrast shows the discussion is not merely physical but spiritual.
Les explains that Paul brings Adam into the text as the first federal head of the human race, and Christ now becomes the culmination of all this because the issue is not just physical but spiritual. He points to verse 46, that the spiritual was not first. The rule throughout Scripture is first the natural, then the spiritual: first Cain, then Abel; first Ishmael, then Isaac; first Esau, then Jacob; first King Saul, then King David. So here it is first Adam, the natural, then Christ, the spiritual.