In the year A.D. 57, Paul was on his third missionary journey, getting ready to go to Jerusalem with an offering from the churches in Greece. Although he knew he had enemies in Jerusalem, he was already thinking about his fourth missionary trip.
Paul wanted to go to Spain, and the best travel route would take him through Rome. This could work out well, Paul thought. There are already Christians in Rome, and they might be willing to support my trip to Spain, just as the Antioch church supported my earlier missionary journeys and the Macedonian churches supported me while I was in southern Greece.
So Paul wrote to the Roman Christians to let them know that he planned to come to Rome and go to Spain — and that he would appreciate some support. However, there was a problem: the Roman Christians had heard some erroneous rumors about what Paul preached. So in this letter, Paul explains what the gospel is, so they will know what they are being asked to support.
For a PDF file covering all 16 chapters of Romans, click here.