The question, "Who wrote the book of Hebrews?" has about 101 different answers. There are a number of factors to consider. The first is I don't think it's a letter, at least not originally. There are all kinds of things about it that are strange for a letter: no greeting, no greeting at the end. I think, most likely, the letter to the Hebrews, as a number of scholars do, originated as a sermon, a speech, given by somebody and written down by somebody. So, I think that's key. Most scholars do not think the apostle Paul wrote it, because Hebrews is different in language from Paul's other letters and different in form. The form can be explained because Hebrews did not originate as a letter. But the language, I think, can be explained by the fact that if, say, Paul preached the message that was later written down, someone else may have written it and put it in their own language. And in fact, if we compare the language of Hebrews to Paul's preaching as recorded by Luke in Acts, all of a sudden, the language starts to sound much more similar. So, I think Paul preached the message of Hebrews and Luke wrote it down. And the Paul of Hebrews sounds like the Paul who we hear preaching through the lens of Luke, if you like, in the book of Acts. And I guess the other thing to consider is Paul's other letters are not addressed specifically to Jewish believers; you know, he's the apostle to the Gentiles. And so, you have to imagine, what would Paul say if he was preaching? And we know that he did preach in the synagogues to Jews. What would he say if he was preaching to the Jews? And I think the letter to the Hebrews, i.e., the sermon to Jews, tells us the answer.