The early Church could not determine whether it was written by Barnabas, by Luke, by Clement, or by the Apostle Paul. Since the Reformation, still greater diversity of opinion has prevailed. Martin Luther assigned Hebrews to Apollos while Calvin believed the writer to be a disciple of the Apostles.
The Roman Catholic Church, in the early part of its history, denied that Apostle Paul wrote Hebrews. The Roman Synod of 382 A.D., however, under Pope Damasus switched the church's position and asserted the book was written by the apostle (1913 Catholic Encyclopedia on Epistle of the Hebrews). One of the reasons for the switch is, "No valid reason has been produced against Paul as the originator of the ideas and the entire contents of the letter" (ibid.).
Internal Evidence of Hebrews
Internal evidence in the epistle offers general information regarding its author.
1) Hebrews was written by a contemporary of the twelve apostles.
2) The book was written before 70 A.D., before the temple's destruction, as a great deal of its content assumes the existence of its services and priesthood (Hebrews 7 - 10).
3) The author commends those to whom the letter is written for their compassion toward him while he was in prison (Hebrews 10:34).
4) The writer was a close friend of Timothy. The author desired to go with him to visit the group to whom the letter is written (Hebrews 13:23).
5) The book itself was written from Italy (Hebrews 13:24).
A General Audience
We cannot consider Hebrews merely as a treatise or discourse. This is because we find certain indications that it was composed as an epistle (letter). The book itself was originally addressed not to the world in general, nor to all Christians, nor even to all Jewish Christians, but to certain individual readers closely and personally connected with the writer.
It is certain the Epistle was addressed primarily to a group composed mostly of Hebrew Christians (Jewish converts to Christianity). Throughout its pages, there is not a single reference to any other class of converts. Familiarity with the Levitical worship, the Temple services, and all the institutions of the Mosaic ritual are assumed. They are in danger of apostasy to Judaism, yet are not warned (like the Galatians and others) against circumcision as they were clearly already circumcised.
The readers to whom the epistle is addressed are also called to consider Jesus the embodiment of the Law and in His person the antitype of the priesthood. His offices are the eternal realization of the sacrificial and mediatorial functions of the Old Testament temple system.
Addressed to a Church
Internal evidence in the book does indicate that, though unknown, it was addressed to a particular church.
1) The members of the church had steadfastly endured persecution and the loss of property.
"But remember the earlier days when, after you were enlightened, you endured much conflict in your sufferings.
"On the one part, you were made a public spectacle by both insults and severe trials; and on the other part, you became companions of those who were enduring the same things. For you not only showed compassion to me in my bonds, but also gladly endured the plunder of your possessions . . ." (Hebrews 10:32 - 34, HBFV throughout).
2) The letter states that those to whom it was addressed had shown sympathy to their imprisoned brethren and to Christians generally (Hebrews 10:32 - 34, 6:10).
3) The church was now in danger of apostasy, and had not yet resisted unto blood.
"You have not yet resisted to the point of losing blood in your struggle against sin . . .
"Therefore, lift up the hands that are hanging down, and revive the weakened knees; And make straight paths for your feet, lest that which is lame be turned aside; but let it rather be healed." (Hebrews 12:4, 12 - 13, see also 5:11 - 6:20).
4) The church had existed for quite a while as many of its leaders had lived a faithful life as a Christian.
"Remember your leaders, who have spoken the Word of God to you, considering the outcome of their conduct; and imitate their faith." (Hebrews 13:7).
5) Prayers are requested so that the writer, who had a personal relationship with the church and had visited it in the past, could visit them yet again.
"Pray for us; for we are certain that we have a clear conscience, in all things desiring to conduct ourselves well. Now I am earnestly exhorting you to do this more diligently that I may be sent back to you more quickly." (Hebrews 13:18 - 19).
6) The readers of the epistle knew Timothy who was a close friend of the Apostle Paul (Hebrews 13:23).
The Jerusalem Church
An argument can be made that the letter to the Hebrews was likely not originally addressed to the Jerusalem church or to any of the other churches in Palestine. Those in Jerusalem and Judea were known for being quite poor and in need of aid (Romans 15:25 - 31, 1Corinthians 16:3). The book, however, is addressed to those whose abundance was used to aid other believers (Hebrews 6:10).
Additionally, while the Holy Land churches had their share of early martyrs (e.g. Stephen, those persecuted by Paul before his conversion, etc.), the church mentioned in the epistle had not yet resisted persecution that threatened their lives (Hebrews 12:3 - 4).
Conclusion
Many early writers like the theologian and historian Jerome (c. 342 - 420 A.D.) expressed doubts concerning the authorship of the book of Hebrews. The Christian scholar Origen (c. 184 - c. 253) stated that, "The writer is known to God alone." Additionally, both church historian Eusebius (c. 260 - 340) and theologian Augustine (354 - 430) also doubted who wrote the book. They all, however, referred to its words as coming from the great mind of Paul.
Though admittedly not conclusive, evidence points to the Apostle Paul being the writer of the book of Hebrews. The epistle follows a general plan similar to the apostle's other writings and its doctrinal sentiments are identical with his. Additionally, there are many points of similarity between the book's phraseology and diction with those of Paul's other thirteen writings.
The Apostle Paul wrote Hebrews at the end of his fourth missionary journey (Acts 28:16 - 30) in the early spring of 61 A.D. He had just arrived in Rome as a prisoner to await his trial before Caesar. Upon completing the epistle, he gave it to Timothy to deliver it to its destination.