Over at Themelios is a good article on “Why Paul Wrote Romans: Putting the Pieces Together,” which gives a good summary of the manifold reasons why Paul wrote: missionary, pastoral, and apologetic. Timmins provides a sensible overview of the textual data, deals with the issues it throws up wisely, and offers insights into recent scholarship too.
What did Paul write Romans? Paul wrote Romans to conduct an apologetic pastoral ministry among the believers of Rome—or a ministry of pastoral apologetics—designed to further gospel mission in Jerusalem, Rome and Spain. Such a ministry was designed to make them obedient to the gospel and, thereby, to further gospel mission in Rome and further afield. But why this letter of pastoral apologetics to enable their obedience to the gospel? Because conflict in their churches and confusion regarding Paul’s gospel centred on the relationship between the gospel and the Jewish Law. Such conflict and confusion stood in the way of the gospel bearing fruit both in their own lives, and in the harvest fields beyond Rome in the west.