The evidence of its use in the Apostolic Fathers is clear, and before the end of the second century it is listed and cited as Paul's.
Verses 14 and 15 each mention groupings of believers and saints.
Claudius died around the year AD 54, and his successor, Emperor Nero, allowed the Jews back into Rome, but then, after the Great Fire of Rome of 64, Christians were persecuted.
Second, the other side of the dialogue is Paul’s conversion and calling to follow Christ in the early 30s.
It is established that there were Jews living in Rome in the times of the Apostles, and that those Jews who had believed [in Christ] passed on to the Romans the tradition that they ought to profess Christ but keep the law [Torah] ...
What nobody doubts is that we are here dealing with a work of massive substance, presenting a formidable intellectual challenge while offering a breathtaking theological and spiritual vision.
The denial of Paul's authorship of Romans by such critics ...
First, Paul was a Hellenistic Jew with a Pharisaic background (see Gamaliel), integral to his identity: see Paul the Apostle and Judaism for details.
His concern for his people is one part of the dialogue and runs throughout the letter.
The external evidence of authenticity could indeed hardly be stronger; and it is altogether borne out by the internal evidence, linguistic, stylistic, literary, historical and theological.
Additionally Phoebe was a deacon of the church in Cenchreae, a port to the east of Corinth, and would have been able to convey the letter to Rome after passing through Corinth and taking a ship from Corinth’s west port.
The contents of the epistle are intended for publicity—they aim at interesting "the public." While some scholars attempt to suggest, like Melanchthon, that it is a type of theological treatise, this view largely ignores chapters 14 and 15 of Romans.