Phoebe is mentioned only once in the New Testament, but a large amount of information can be garnered from that one passage.
I commend to you our sister Phoebe, who is a deacon in the church in Cenchrea. Welcome her in the Lord as one who is worthy of honor among God’s people. Help her in whatever she needs for she has been helpful to many, and especially to me. (Romans 16:1-2)
Phoebe obviously played a key role in the early church in Cenchrae.
The word “deacon” here is translated in other versions as “servant” (for example, the NKJ version), but it is more likely that she is being described as a recognized leader in the church, similar to the 1 Timothy 3:11 use of the word about women as deacons. (NB: It takes being a servant to lead.)
Another word used to describe Phoebe is prostatis, translated here as helpful. It is a feminine word, which according to Strong’s concordance means “a woman set over others, or a female guardian, protectress, patroness.” It is a feminine version of the word proistemi which means “to be over, to superintend, to preside over” amongst other things. It’s from the same word used in Romans12:8–“he who leads, with diligence.” The word certainly holds connotations of leadership. Paul includes himself as one who has been “helped” (led) by her. Interestingly, it’s not the same word used for help earlier in the sentence. That is a word meaning “one who stands by.” Paul could have used that word again, but instead chose prostatis.
Since Paul commends Phoebe, and asks people to receive her, as opposed to sending her greetings as he does to the other people listed in Romans 16, most people think that Phoebe is the one who had been entrusted to carry the letter to the Romans.
(I obtained much of the source ideas for this from Philip B. Payne’s book Man and Woman, One in Christ: An Exegetical and Theological Study of Paul’s Letters.)