Rev. Anderson writes that, "each of [Paul's letters] addresses particular issues and arguments within the community to whom he was writing." Although he never preached in Rome, yet converted many in Galatia, he had much of the same message in both letters. The primary issue that is addressed by Paul in his letters is how to assimilate the Old and New covenants--the communities as a mixture of Jews and Gentiles were beginning to live their Christian faith together. As their traditions and newfound teachings would clash, arguments would arise.
Paul's letters were written with love and concern for the communities to which he sent them. And as these conflicts would arise, his letters helped these communities to work through divisions and act lovingly towards one another.