v14-16 Knowing that the Roman believers are not perfect Paul does not find fault with them but brings out the positive things he sees in them. He notes they are full and filled and able. And then he goes on to give them (and us) instruction and admonishment in their care for one another.

v16-17 a reminder that Paul did not choose service and reminds us that it is a blessing to serve Christ and tells us that he is the minister to the Gentiles

v18-20 Paul wants to preach the Gospel of Christ where it had not already been taught.