That this Epistle is entitled to a place in the New Testament Scriptures has been discussed but little in comparison with the question of its authorship. It is quoted at large by Clement of Rome before the close of the first century, by Ignatius, Polycarp, Justin Martyr, Irenaeus, and others in the second century, is found in the Versions of the second century, is named in the Ancient Canons, and is affirmed to be a part of the Holy Scriptures by the Council of Antioch (A. D. 269) and of Nice (A. D. 325); as well as by the later councils.
On the other hand, both the ancient and modern church have been divided concerning the writer to whom it is to be ascribed. Contrary to the usual custom the writer's name is not given in the opening verses, nor in the closing salutations. It differs somewhat in style from any other portion of the New Testament. Some have thought it improbable that Paul, the Apostle to the Gentiles, should have addressed an Epistle to the Hebrews; for these, and perhaps other reasons, many devout critics have held that it was written by Barnabas, or by Apollos, or by Luke, and even Clement of Rome has been named as the author. In the ancient church the East with one consent declared in favor of Paul, while the West asserted that it belonged to some other writer, though in modern times the Latin Church has decided the question by the weight of infallibility in favor of the apostle to the Gentiles. Luther and Calvin both held that it was not Pauline, and have been followed by many moderns.
The limits of this work will not allow details concerning this discussion, and I will content myself with briefly stating reasons why I think it is to be ascribed to Paul. (1) There is no proof whatever, of any kind, that any one else was the author. There is only conjecture. (2) Paul is named as the author in the second century by Christian Fathers who were the disciples of men who had sat at the feet of the apostles. (3) The greatest of the Ante-Nicene Fathers who make mention of its authorship affirm that it was written by Paul. (4) It was written in Paul's lifetime, for the temple was evidently still standing; it was written by a friend of Timothy, written from Italy, and evidently by one who was a prisoner. (5) The salutation, or benediction with which it closes is found in the other thirteen epistles of Paul, and is found in the New Testament epistles of no other writer. Paul alone invokes grace upon those whom he addresses as his farewell words. (6) The second Epistle of Peter, an Epistle evidently written to Hebrews, declares that Paul had written an Epistle to them. "As our beloved brother Paul, according to the wisdom given to him hath written unto you; as also in all his Epistles."
This refers to some particular letter, sent to the same persons whom Peter was addressing, and hence there seems to be little doubt that there existed, before Peter died, an Epistle to the Hebrews written by Paul. (7) The argument is thoroughly Pauline. There can be no doubt, even if the language is not Paul's, that he inspired the thoughts. Hence, we are justified in concluding that the Epistle is really one of Paul's, even if his thoughts are in part clothed in the language of another writer.
It is addressed to HEBREWS; evidently Hebrew Christians; probably not so much those of Jerusalem as the "Dispersion," the multitudes of Jewish Christians in Gentile 
lands. It shows that those addressed were persecuted, were in danger of being tempted to fall away, that they had not yet shed their blood for Christ, and, in order to strengthen them, the superiority of Christianity to Judaism is demonstrated by showing the superlative excellence of Christ. He is (1) superior to the prophets;
(2) superior to the angels;
(3) superior to Moses.
(4) His priesthood is superior to that of Aaron, being a priest after the order of Melchizedek.
(5) Then the superiority of the New Covenant to the Old is shown, being a better covenant, based upon better promises. This is shown in
Chs. 8, 9, 10,
and then follows in the remaining chapters an exhortation to steadfastness, based upon faith and strengthened by examples of the heroes of the faith.
It is evident from the closing words, whatever may have been the writer's reasons for not incorporating his name in the Epistle, that he was well known to those addressed. He asks their prayers, prays for them, speaks of visiting them with Timothy, and closes with the usual Pauline farewell benediction.