There are several mentions of Priscilla in the New Testament. The first is in Acts 18 where she instructs Apollos:
Acts 18:1 After this Paul departed from Athens and went to Corinth. 18:2 There he found a Jew named Aquila, a native of Pontus, who had recently come from Italy with his wife Priscilla, because Claudius had ordered all the Jews to depart from Rome. Paul approached them 18:3 and because he worked at the same trade, he stayed with them and worked with them (for they were tentmakers by trade)...
18:19 When they reached Ephesus, Paul left Priscilla and Aquila behind there, but he himself went into the synagogue and addressed the Jews...
18:24 Now a Jew named Apollos, a native of Alexandria, arrived in Ephesus. He was an eloquent speaker, well-versed in the scriptures. 18:25 He had been instructed in the way of the Lord, and with great enthusiasm he spoke and taught accurately the facts about Jesus, although he knew only the baptism of John. 18:26 He began to speak out fearlessly in the synagogue, but when Priscilla and Aquila heard him, they took him aside and explained the way of God to him more accurately.
The next is in Romans where Paul uses the term synergoi, colleague to refer to her:
16:3 Greet Prisca and Aquila, my colleagues in Christ Jesus, 16:4 who risked their own necks for my life. Not only I, but all the churches of the Gentiles are grateful to them.Co-worker which is how the word is often translated is too weak. This term can even be used as a euphemism for sex (though I'm not arguing or implying Paul means it that way), colleague, good friend perhaps. What the word is never used for is a subordinate, while the word in "co-worker" in English can imply a subordinate. That is Paul considers Priscilla an equal, he is addressing her as an equal. This means that at least in Paul's mind she is not beneath him either directly or diagonally. This rules out the usually counter claimto Priscilla being a leader, that Aquila was a peer and Prisca worked under Aquila, because then Priscilla would be a diagonal subordinate and the word choice would be inappropriate.
I'd point to 1Cor 3:9 shows again Paul stating that he and Apollos are working together, another use of synergoi, not that Apollos works for Paul. When one reads 1Cor 3 the whole point of the chapter is rejecting the sort of hierarchy which would put one or the other on top; Jesus is on top.
Then in first Corinthians he mentions how she runs a house church (this one in Emphasis):
1Cor 16:19 The churches in the province of Asia send greetings to you. Aquila and Prisca greet you warmly in the Lord, with the church that meets in their house.Finally in 2Tim 4;19 he greets them again indicating they travel as well:
2Tim 4:19 Greetings to Prisca and Aquila and the family of Onesiphorus.As can be seen above, Priscilla is mentioned before Aquila in (Acts 18:18,26, Rom 16:3, 2 Tim 4:19). The reason this is so key, is that normally the man would be named first or exclusively; meaning she is the better known and more prestigious of the two. And this is occurs in books addressed to various cities, so she is not just some well known/respected person locally rather she is well known and respected within the whole of the Christian community; and better known and more respected than Aquila.
Moreover there is strong evidence according to the experts that the shift in Acts 18:2 was a later change. Ben Witherington for example in he anti-feminist tendencies of the "Western" text in Acts (Journal of Biblical Literature 103 no 1 Mr 1984, p 82-84.) mentions the shift of Acts 18:2 and argues that Priscilla was consistently named first. Metzger in the textual commentary on the NT has this verse with Priscilla named first and gives the same reason. The Teachers' Commentary on the Acts of the Apostles By Francis Nathan Peloubet, is cited by both as for the importance of this shift (i.e. diminishing her role).
So in other words we have Prisca approximately equal to Paul in Paul's mind; and Priscilla generally regarded as well above Aquila by the broad Christian community. Those two facts together are strong evidence of the extent of her leadership. But there is even more evidence. In Acts 18:26 she is portrayed as teaching a theologian about theology. Again she is listed first, with regard to the act of teaching. And this is devastating to the argument that women should not teach because it means that she is well respected as a teacher / missionary not because of some secondary factor.
Karl Josef Rudolph Cornely in Commentarius in ep. ad Romanos" (Paris, 1896) collected the various ancient authorities on this subject and there seems to be agreement that Prisca is the more important of the pair since otherwise she would never be named first. Chrysostom held a similar opinion regarding her being named first indicated she was the teacher of Apollos.
This too is worthy of inquiry, why, as he addressed them, Paul has placed Priscilla before her husband. For he did not say, “Greet Aquila and Priscilla,” but “Priscilla and Aquila.” He does not do this without reason, but he seems to me to acknowledge a greater godliness for her than for her husband. What I said is not guess-work, because it is possible to learn this from the Book of Acts. [Priscilla] took Apollos, an eloquent man and powerful in the Scriptures, but knowing only the baptism of John; and she instructed him in the way of the Lord and made him a teacher brought to completion (Acts 18:24-25). (John Chrysostom, “First Homily on the Greeting to Priscilla and Aquila”)In his commentary on 2Tim he says essentially the same thing. Incidentally in Homily 40 on Acts he indicates Paul left them in Ephesus specifically so they could teach. Again another direct reference to Priscilla being a teacher.
The current Pope commented on church tradition, "Later hagiographic tradition has given a very singular importance to Priscilla, even if the problem of identifying her with the martyr Priscilla remains."
A few more pieces of evidence are archeological. In Rome to this day there is still a street named after her (but not him) in the aventine Via de Santa Prisca. There is a large church built in her honor, that goes back to the 4th century and possibly earlier, which legend says was the location of her house. Incidentally under the church was a mithric temple, so it may have been that Prisca's "house church" was really quite nice, a converted temple, it also contains Christian catacombs from no later than the 2nd century. Her grave still has veneration.
So to summarize the bible teaches
- Paul does not consider her an inferior.
- That she outranked Aquila.
- That she taught theology.
- Church fathers agree she was a teacher.
- As that the interpretation of her being named first indicating primacy was upheld in both the ancient and modern world.
- Archeology indicates she was the more important of the pair.