Philip Schaff's Popular Commentary (4 vols)
Romans 1 - Introduction
Address, Introduction, and Theme
Chapter 1 contains two distinct parts: Romans 1:1-17 form the introductory portion of the Epistle; Romans 1:18-32 give the proof that the Gentiles need the gospel from the fact of their sinfulness exposing them to the wrath of God. (This statement is the first half of the first main division of the doctrinal part of the Epistle. See Introduction §3, in the Romans Book Comments and notes on Romans 1:16; Romans 1:18.) We divide Romans 1:1-17 into three sections: Romans 1:1-7 contain the Address and Greeting (in an unusually full form); Romans 1:8-15 constitute the Introduction proper, since they give the occasion for this Apostle's writing to the Roman Christians; by an easy transition he then passes to the Main Theme of the Epistle, which is stated in Romans 1:16, and further explained in Romans 1:17.