
As Paul begins to close out his letter he deals with the possibility of his motives for writing being misunderstood. Since he'd had no direct contact with the church in the past, some might have wondered why he'd suddenly be writing them and writing, at least in some cases, rather directly.
To explain, Paul refers to his mission and how the Roman Christians are part of that mission. He goes on to glorify God for the role he's allowed him to have in that mission, a unique mission, to preach the gospel where it had never been preached.
Notes for this sermon can be found here.