The book of Hebrews was written to Jewish Christians about 64-69 AD, prior to the destruction of the Herodian or Second Temple in 70 A.D. by the Romans.
The likelihood of Jerusalem being the destination of the letter is promoted by Wescott, who states, “Nowhere else would the images of sacrifice and intercession be constantly before the eye of a Jew.” However, Ryrie prefers Italy because of 13:24, “Those from Italy greet you,” and because of the use of the Septuagint (written in Greek), instead of Hebrew, to quote Old Testament passages. Hodges suggests the ancient Libyan city of Cyrene in North Africa as the destination, with Barnabas as a possible author. This would make Hebrews of apostolic origin since Barnabas was called an apostle (Acts 14:4, 14).
In the first century, new churches usually formed in synagogues. Prior to emerging from its “Jewish womb,” the church faced “a major crisis in understanding itself as a universal faith and how it [was] to relate to its Jewish roots.
Hodges notes that, “…the author’s heavy stress on Jewish prototypes and his earnest polemic against the permanence of the Levitical system are best explained if the intended audience of the book of Hebrews was largely Jewish and inclined to be swayed back to their old faith.” The number of times words such as sin (27) priest (26), blood (23), sacrifice (19), law (13), offering (10), and tabernacle (9) are used by the author reveal the book’s focus on the Levitical system of sacrifice.
Throughout the book of Hebrews, the author is presenting Christ and Christianity as superior to Judaism and the Levitical priesthood. The theme of the book is the superiority of Christ, as the writer presents Jesus as superior to the prophets and angels, and the “exact representation of [God’s] nature” (1:3). The eternal priesthood of Christ, after the order of Melchizedek, is shown to be superior to the Levitical priesthood, which was temporary in nature. The writer argues for the cessation of the Levitical priesthood and sacrificial system of worship. The word covenant appears 21 times in the book of Hebrews to emphasize the new covenant, mediated by Christ (12:24), which made the old [Mosaic] covenant obsolete (8:13).
The Hebrew believers were under pressure from the Jewish community to give up Christianity and return to their ancestral faith. The author of Hebrews repeatedly warns against any Jewish believers who are tempted to become apostate. It is significant that “Josephus and Eusebius record that for the Christianity’s first decades it remained a sect of Judaism.”
So the author to Hebrews admonishes these Jewish believers to grow in their newfound faith (occurring 33 times) in God and challenges them to put aside their reliance on the dead works of Judaism (6:1; 9:14). Faith is a major theme in the book of Hebrews as evidenced by the “Hall of Faith” in chapter 11.
Warning Passages. The five warning passages in Hebrews were addressed to Jewish believers who failed to grow spiritually. They were warned not to “drift away” by neglecting “so great a salvation” (2:1-4). They were rebuked for their lack of faith, and warned against having an “evil, unbelieving heartthat falls away from the living God” (3:1-4:16). They had become “dull of hearing”, having failed to “have their senses trained to discern good and evil,” and now they were being warned of the impossibility of being renewed to repentance (5:11-6:20). After being cautioned that to “go on sinning willfully” would result in severe punishment, they were challenged to “hold fast the confession of [their] hope without wavering” (10:19-39). Then in 12:1-29, they are admonished to “consider Jesus,” and endure discipline in order to “share His holiness,” because “our God is a consuming fire.”
Hebrews 6:4-6. Following a challenge to “press on to maturity” (6:1), in verse 4 the author makes a warning. The use of the pronouns is changed from you and we to those, indicating that the author is referring to a specific group of people. Perhaps they are acquaintances of the Hebrew Christians. Maybe they even attended the same church.
The author documents the fact that those refers to believers, listing four one-time occurrences, verified by the use of the word once, and the aorist tense (referring to a point in time).
For in the case of those who have once been enlightened and have tasted of the heavenly gift and have been made partakers of the Holy Spirit, and have tasted the good word of God and the powers of the age to come (6:4, 5).
The word enlightened, also used in 10:32, is likely a synonym for the salvation experience.
For God, who said, “Light shall shine out of darkness,” is the One who has shone in our hearts to give the Light of the knowledge of the glory of God in the face of Christ (2 Cor. 4:6).
Those who have once-and-for-all “tasted of the heavenly gift” have received the free gift of eternal life.
For the wages of sin is death, but the free gift of God is eternal life in Christ Jesus our Lord (Rom. 6:23).
They have become “partakers [sharers] of the Holy Spirit.” This is the result of the indwelling of the Holy Spirit in the life of a believer at the moment of salvation.
However, you are not in the flesh but in the Spirit, if indeed the Spirit of God dwells in you. But if anyone does not have the Spirit of Christ, he does not belong to Him (Rom. 8:9).
These believers have also “tasted the good word of God and the powers of the age to come.” Some claim this refers to Christian preaching and the miracles that accompanied it (cf. Mk. 16:20; Acts 2:22; Gal. 3:5).
Hebrews 6:6. This is considered by many to be the most difficult verse to interpret in the entire New Testament.
and then have fallen away [stumbled or went astray], it is impossible to renew [restore] them again to repentance, since [while] they again crucify to themselves the Son of God and put Him to open shame.
The impossibility of renewing them to repentance cannot refer to loss of salvation because the Scriptures teach that believers cannot lose their salvation (John 3:16; 10:27, 28; Rom. 8:1, 38, 39).
Following the use of the word impossible in Hebrews 6:6, the author uses it again in three more verses: “It is impossible for God to lie” (Heb. 6:18). “For it is impossible for the blood of bulls and goats to take away sins” (Heb. 10:4). “Without faith it is impossible to please Him” (Heb. 11:6).
It is also impossible for a believer to be restored to fellowship and walk by faith while relying on the dead works of Judaism. This is the dilemma of some Jewish believers in the book of Hebrews. They failed to understand that believers who are led by the Spirit are not under the Law (Gal. 5:18).
Opinions about this verse continue to be debated. The Arminian view teaches that these are believers who have lost their salvation. The Calvinist view argues that they never were believers. The hypothetical view teaches that the events had not actually occurred. The Apostate view states that these Jewish believers, “who reject the truth of Christ’s efficacious sacrifice have no other provision for sin.” They can never be restored to fellowship. They have been disqualified for further service, and have lost their eternal rewards.
But if these are Jewish believers who have committed acts that prevent them from ever being restored to fellowship with God, as some claim, then they would be guilty of the sin unto death (1 John 5:16, 17). Hodges states that, “Following the words ‘those who’ is a description of the persons whom the writer affirmed cannot possibly be brought back to a state of repentance.”
But the inability to be renewed to repentance in 6:6 appears to be conditional upon those Jewish believers continuing to “crucify to themselves the Son of God and put Him to open shame.” It appears that some Jewish believers had been persuaded to return to Judaism—perhaps exclusively or maybe only partially. Radmacher, Allen and House summarize, “If the original readers were Christian Jews contemplating returning to Judaism, then they were joining the ranks of those who crucified Christ. It amounts, in essence, to a fresh public rejection, a crucifixion (symbolically) of Christ all over again.”
When Jewish believers brought an animal to the Jewish temple to be sacrificed, they were identifying themselves with the unbelieving Jews who had crucified Christ. Apparently this act was tantamount to a pubic rejection of Jesus Christ—a declaration that His death was insufficient. This is further clarified in Hebrews 10:29:
How much severer punishment do you think he will deserve who has trampled under foot the Son of God, and has regarded as unclean the blood of the covenant by which he was sanctified, and has insulted the Spirit of grace?
The challenge for the Jewish believers to whom Hebrews is written is to reject the ancient Jewish sacrificial system in favor of the ultimate, once-and-for-all sacrifice of Christ. They can’t have both. The author is saying that it is either/or. Christ or Judaism. Those Jewish Christians to whom the author is referring can’t be restored to fellowship with Christ unless they lay aside the dead works of Judaism and replace them with faith. This is the condition that is required of those believers in order for God to “renew them again to repentance.” The author is warning his Hebrew audience not to duplicate the actions of those Jewish believers.
In Hebrews 6:7 and 8, the author illustrates the danger of a Jewish believer returning to Judaism. He uses a metaphor of the land to contrast believers who have grown in Christ and are blessed with those whose works are worthless and are in danger of being cursed, and will be eventually burned. McGee summarizes, “So the writer of Hebrews is talking about the fruit of salvation, not about the root of salvation.”
In essence, this is the warning for the Jewish-Christian recipients of the book of Hebrews: Don’t be like those Jewish believers who have turned away from Christianity to once again practice Judaism. Don’t revert to the Levitical system of sacrifice under the Mosaic Law like those who have returned to their ancient faith. Rather, grow in maturity in Christ, the Son of God, a priest forever after the order of Melchizedek. Set aside dead works. Grow in your faith so you will be blessed by God.
After warning the Hebrews about the possibility of God’s punishment and loss of rewards for those who were practicing dead works, the writer now attempts to stimulate them to continue in the faith. Verse 9, begins with but, a word which contrasts the negative outcome of the previous verse, “But, beloved, we are convinced of better things concerning you, and things that accompany salvation, though we are speaking in this way” (6:9). The word you now replaces the reference to those of the previous verses. The warning is over; the challenge to maturity continues.
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Therefore, since we have so great a cloud of witnesses surrounding us, let us also lay aside every encumbrance and the sin which so easily entangles us, and let us run with endurance the race that is set before us, fixing our eyes on Jesus, the author and perfecter of faith, who for the joy set before Him endured the cross, despising the shame, and has sat down at the right hand of the throne of God (Hebrews 12:1, 2).
 Westcott, Brooke F. (N.D.). The Epistle to the Hebrews, Grand Rapids, MI: Eerdmans Publishing.
 Hodges, Z. C. (1985). Hebrews. In J. F. Walvoord & R. B. Zuck (Eds.), . Vol. 2: The Bible Knowledge Commentary: An Exposition of the Scriptures (J. F. Walvoord & R. B. Zuck, Ed.) (778). Wheaton, IL: Victor Books.
 Radmacher, E. D., Allen, R. B., & House, H. W. (1999). Nelson’s new illustrated Bible commentary (Heb 6:6). Nashville: T. Nelson Publishers.
 McGee, J. V. (1991). Vol. 51: Thru the Bible commentary: The Epistles (Hebrews 1-7) (electronic ed.) (109). Nashville: Thomas Nelson.