While some people in the early church believed that Paul wrote the Epistle to the Hebrews, there is no explicit indication of the author in the letter itself, whereas in all Paul's known letters he takes great care to identify himself as the author. Both the content of Hebrews and the style of the Greek distinguish it from Paul's known letters; and Hebrews is clearly addressed only to Jews, or at least to people who were exceedingly famililar with the Jewish scriptures, whereas Paul's letters are addressed to churches made up of both Jews and Gentiles.
It is entirely possible that the author did originally identify himself at the start of the letter and that for some reason this part was either lost or deliberately removed. It might have been removed or never have been included because any letter claiming that Jesus was Lord rather than Caesar could have spelt imprisonment or death for its author if he could be identified. But another reason for anonimity might have been simply that the author was a woman. Paul had forbidden women to teach in church, and while prophetesses were common both in the church and in the Greek-Roman culture of the time, female teachers, even of children, were almost entirely unknown.
If the author of Hebrews or at least of the main part of the letter was a woman, then the most obvious candidate would be Priscilla, the wife of Aquila...
After this [Paul] left Athens and went to Corinth. And he found a Jew named Aquila, a native of Pontus, lately come from Italy with his wife Priscilla, because Claudius had commanded all the Jews to leave Rome. And he went to see them; and because he was of the same trade he stayed with them, and they worked, for by trade they were tentmakers... After this Paul stayed many days longer, and then took leave of the brethren and sailed for Syria, and with him Priscilla and Aquila... Now a Jew named Apollos, a native of Alexandria, came to Ephesus. He was an eloquent man, well versed in the scriptures... though he knew only the baptism of John. He began to speak boldly in the synagogue; but when Priscilla and Aquila heard him, they took him and expounded to him the way of God more accurately. (Verses from Acts chapter 18. The last part must have taken place before Priscilla and Aquila left for Syria with Paul, or else later if and when they had returned.)
Acts chapter 18 tells us that Paul knew the married couple well, that they worked together with him in ministry, that they taught other believers, and probably that Priscilla, whose name Luke put first, was regarded as the leader in their joint ministry. At the end of Paul's last known letter, 2 Timothy, he send greetings to 'Prisca and Aquila', using a diminutive of her name which only a very close friend would have done!
One reason I have always thought that Hebrews was the work of Priscilla or at least the joint work of her and her husband, is the frequent use of the word 'we' rather than 'I'. Paul does sometimes write 'we' but he nearly always says 'I', especially when he wants to emphasize his personal authority as an apostle. In Hebrews this is not the case, at least it isn't the case in the first eleven chapters.
Hebrews 5:11: 'About this we have much to say which is hard to explain, since you have become dull of hearing.'
Hebrews 6:9: 'Though we speak thus, yet in your case, beloved, we feel sure of better things that belong to salvation.'
Hebrews 8:1: 'Now the point in what we are saying is this...'
And so on.
Another reason I have thought that a woman was involved is that the whole of chapter 11 is about Old Testament people. Women tend to be more people-centred than men are, but this chapter also has an unusual emphasis on female people. Three of the people mentioned are women - Sarah the wife of Abraham, Pharoah's daughter and Rahab the harlot, while in verse 35 it says, 'Women received their dead by resurrection', no doubt a reference to the Shunammite woman whose son was raised from the dead by Elisha. In fact the author attributes the existence of the Jewish nation to Sarah rather than Abraham! 'By faith Sarah herself received power to conceive, even when she was past the age, since she considered him faithful who had promised. Therefore from one man, and him as good as dead, were born descendants as many as the stars of heaven and as the innumerable grains of sand by the seashore.'
Today, however, I had a new insight into the authorship of Hebrews. In the final chapter the last seven verses repeatedly use the pronoun 'I' instead. For example, 'I urge you the more earnestly to do this in order that I may be restored to you the sooner... I appeal to you, brethren, bear with my word of exhortation, for I have written to you briefly.'
Those last words - 'for I have written to your briefly' - always made me smile, for the Epistle to the Hebrews is hardly brief. But this morning I realized that this last thirteenth chapter, which uses the pronoun 'I' rather then 'we', is indeed a list of brief exhortations, whereas the first eleven chapters, which use 'we', comprise teaching rather than exhortation. So it seems to me that while Priscilla almost certainly wrote the first eleven chapters writing 'we' to cover herself as a female teacher by aligning herself with Aquila, her husband Aquila finished it off by writing some brief closing words of exhortation and salutation in the final chapter, stamping his authority on the whole thing by means of the prounoun 'I'.
The penultimate twelfth chapter uses neither 'we' nor 'I', so in theory it could have been written by either Priscilla or Aquila. But I believe it is Priscilla's, since it is the conclusion to be drawn from the examples of the heroes of faith she listed in the previous chapter 11. It is true that it mainly comprises exhortation rather than teaching, but it is exhortation written in a different style from Chapter 13, and it doesn't fit the adjective 'brief' in the same way that Chapter 13 does. Apart from a few verses Chapter 13 is simply a list of bullet points.
The few verses in Chapter 13 that are not bulleted exhortations relate once more to Jesus's abolition of animal sacrifice, a major theme of the earlier chapters, so either Priscilla felt she had to chip in to what Aquila was writing, or else Aquila thought it wise to draw a conclusion from what she had written as a way of authenticating her teaching. In either case these verses, by referencing earlier chapters, demonstrate that Chapter 13 was not an entirely separate letter, and that both authors, while writing in different ways, were doing so together.
In conclusion I believe that the Epistle to the Hebrews was written by Priscilla, the wife of a Roman Jew named Aquila, apart from the final chapter which was mainly or entirely Aquila's own handiwork.
It that is the case, what does it tell us? The Epistle to the Hebrews is a vitally important component of the New Testament. Among other things it explains why the Jewish sacrificial system, instituted by God, is no longer a necessity in order for people to remain in God's favour. Making sacrifices at the temple in Jerusalem was already becoming a practical impossibility for Jews scattered across the Roman empire, and for Gentile believers it was essential to explain that God didn't require them to engage in temple sacrifices as Jews did. Hebrews explains from scripture how Jesus the Son of God has inaugurated a new and better covenant that replaces the old one, by means of a final and perfect sacrifice of himself to his Father, and it encourages believers subject to persecution and the threat of death to remain faithful to Christ, who through death entered into glory just as they will.
So we see that even in a male-dominated culture God was pleased to use a woman to teach these profound truths to both men and women, with the approval of her husband ('we') and under his authority. Priscilla's authorship of this amazing letter is an antidote to Paul's refusal to allow women to teach men, a rule that arose out of the culture of his time, to the fact that in general women were not nearly so educated or versed in the scriptures as men were, and from Paul's conviction that women are more easily led astray than men and can therefore cause trouble (cf Adam and Eve; Ahab and Jezebel; Solomon and his wives).
If there was originally an introduction to the letter that identified Priscilla and Aquila as the authors, I believe it would have run something like this:
'From Aquila, a servant of Jesus Christ and a fellow worker with the apostle Paul, together with his beloved wife Priscilla who is a joint partaker of the heavenly kingdom to come, to all God's chosen people in Rome and elsewhere whose hope is in Jesus the Son of God for a promised salvation ready to be revealed in this last time, greetings. In many and various ways God spoke of old to our fathers by the prophets...'