I think it is clear that Phoebe was a high ranking representative of the church of Cenchrae who was sent by Paul as his representative to deliver the highly sensitive document known as the Epistle to the Romans to the many disparate churches in Rome. He cites her rank and title by way of introduction to the churches. If he were guilty of exaggerating her position, it could end up being a big mistake.
Think about how significant this woman Phoebe was. Paul entrusted her with the task of delivering his epistle into the midst of a very explosive situation.
After Claudius kicked out the Jews, the Christian churches lost their entire church leadership, leaving Gentiles to arise to the occasion of taking over leadership of their churches. Thus, overnight, the churches in Rome flipped from being predominantly led by Jews, over to not having any leadership, and then over again to be being led by those less familiar with the Old Testament.
All this was enough turmoil in and of itself. But when Claudius' ban was lifted a few years later, many if not most of those Jewish Christian leaders returned to Rome, expecting to be reintegrated back into church leadership.
Imagine, as pastor of your church, the previous pastor showed up expecting to resume his ministry!
Meanwhile, while the Jews were away, the Gentiles gave up living like Jews, and they ate all meats. Which was fine, until the Jewish Christians showed up again. Thus, you have chapters 13-15 of Romans.
So, Paul wanted to say a positive word to help the Jewish and Gentile Christians to get along with each other, to be altogether united. But his big goal was to solicit sponsorship for his Spanish mission and to see if any of the Christians in Rome had ties to the Roman administration in Spain (or at least, this latter point has been deduced by Robert Jewett in his massive Hermenia commentary on Romans).
At any rate, the whole situation was extremely sensitive. And so Paul sent his best man to handle the job, which, in this case was a woman. She was no ordinary lowly servant-girl of the Lord. Jewett brings us up to date on where scholarship is today in regard to Phoebe the deacon:
Although earlier commentaries interpret the term διάκονος as a subordinate role,
it now appears more likely that she functioned as the leader of the
congregation. That διάκονος was an official title of leadership has been shown
by Borckhaus and Holmberg, and is strongly indicated by earler references in Rom
11:13; 12:7; and 13:4. In the light of its use in 1 Cor 3:5; 2 Cor 3:6; 6:4;
11:15 and 23 to refer to missionaries, including Paul himself, it is no longer
plausible to limit her role to philanthropic [i.e., womanly] activities.
Fiorenza contendst that... '[she] is a missionary entrust with preaching and
tending churches...It can be concluded, therefore that Phoebe is recommended as
an official teacher and missionary in the church of Kenchreia.' However, in the
light of the possessive qualification, 'deacon of the church in Kenchriea,' it
seems more likely that she functioned as a local leader rather than as a
As it turns out, the big reason why earlier commentators thought that the term διάκονος meant a lowly servant here and not a church leadership position in 16:1 was simply because Phoebe was a woman! An honest look at comparable usage pushes the conclusion that Phoebe was indeed Deacon of Cenchrae, and that Paul entrusted her with this significant responsibility of organizing a support network for his Spanish mission.Why would Paul entrust such a big job to a woman? Perhaps because so many of the church groups in Rom 16 were headed up by women.