Scholars often have difficulty assessing whether Romans is a letter or an epistle. A letter is something non-literary, a means of communication between persons who are separated from each other. Confidential and personal in nature, it is intended only for the person or persons to whom it is addressed, and not at all for the public or any kind of publicity. An epistle is an artistic literary form, just like the dialogue, the oration, or the drama. The contents of the epistle are intended for publicity. Perhaps this was an essay-letter. Was this a summary of all Christian doctrine? Paul sometimes used a style of writing common in his time called a “diatribe”. He appears to be responding to an imaginary heckler. He asks ironic questions. Certainly, this was a public letter or epistle. What kind of letters do you write?