Romans 1:14-15

I am obligated both to Greeks and non-Greeks, both to the wise and the foolish. That is why I am so eager to preach the gospel also to you who are at Rome.

(v14-15, NIV)

In what way is Paul obligated to these people? He seems to cover all his bases in naming these people he's obligated to. They could either be Greeks or non-Greeks. Other translations say "Greeks and barbarians". Either way, he also includes both wise and foolish. These are the people he seems to be obligated to. His obligation leads him to preach the gospel, so that should give us an insight into how he is obligated to these people.

One way in which Paul is obligated to preach the gospel is because of his calling. God has called him and instructed him to preach the gospel. He is as all followers of the Lord Jesus Christ are to preach the gospel and tell everybody the good news. They do not have the good news, so Paul is to tell them the good news. Paul is continuing to be submissive and obedient to the will of God.