A dispensational continuity exists concerning salvation in the Gospels, through the Book of Acts and the Book of Hebrews. We can find eternal security (Heb. 7:25), a new covenant (Heb. 10:9), the ONE sacrifice as opposed to animal sacrifices (Heb. 10:8-12), Jesus, the AUTHOR and FINISHER OF OUR FAITH (Heb. 12:2), the Mediator of the new covenant (Heb. 12:24), grace (Heb. 13:9), the new covenant sacrifice of praise (Heb. 13:15). Can we assume Paul expected to be with the tribulation saints shortly (Heb. 13:23-25) or did he ask the future tribulation saints to pray for him (Heb. 13:18)? Is salvation in the Book of Hebrews the same as the salvation previously spoken by Jesus?
[The quotation of Hebrews 2:3-4 actually proves the MAD position to be correct. It shows that the salvation being spoken of in Hebrews is one that began with the Earthly ministry of Christ, NOT the salvation message revealed to Paul, which was a "mystery" revealed to him by the Lord from Heaven (Gal. 1:11-12, 2:7-8, Eph. 6:19, Titus 1:1-3, Rom. 2:16, 16:25, 2 Tim. 2:8, 1 Tim. 1:11-16). The gospel of the grace of God was committed to Paul and was made the "pattern to them which should hereafter believe".
Before going any further, let me remind you that some of the more obvious reasons that Hebrews is not written about the Dispensation of Grace (neither Jew nor Gentile) is that it is called "HEBREWS". It is written to the "LAST DAYS" (1:2) and the "END OF THE WORLD" (Heb. 9:26). The writer of Hebrews plainly says that he is speaking about the "WORLD TO COME", the Millennium (also see Mark 10:30 and Luke 18:30).
Also before going any further, I would like for you to supply a proof text that Paul wrote HEBREWS. Saying as he is the apostle of the GENTILES (Rom. 11:13, Eph. 3:1, 1 Tim. 2:7, 2 Tim. 4:17). Paul and Barnabas were to "go unto the HEATHEN" and Peter/James/John went to the circumcision (Gal. 2:9). There is certainly no scriptural evidence that Paul wrote Hebrews. The first word in every one of Paul's epistles, Romans-Philemon, is the word "PAUL". Every epistle begins with that word. 2 Thessalonians 3:17 says, "The salutation of Paul with mine own hand, which is the token in every epistle: so I write." There is no salutation of Paul in Hebrews. Also, Paul considered his six chapter letter of Galatians to be a "large letter" (Gal. 6:11), but the writer of Hebrews considered this 13 chapter epistle to be "few words" (Heb. 13:22). These epistles could not possibly have the same author.
Answering your first point, there is no eternal security in Hebrews. The Hebrews are not part of the house of God unless they hold fast their confidence and rejoicing of hope firm into the end (Heb. 3:6). Wherefore they must take heed lest any of them depart from the living God (Heb. 3:7, 12). The Hebrews are made partakers of Christ IF they hold the beginning of their confidence stedfast unto the end (Heb. 3:14). If the Hebrews did not hold their confidence and faith firm and stedfast unto the end, they would not enter into God's rest, the Millennium/Land (Heb. 3:14-4:1). The promise of entering into the rest will leave them and they will come short of it (Heb. 4:1). The Hebrews have to LABOR to enter into that rest and their works will NOT cease until they enter into it (Heb. 4:10-11). Just as Christ learned obedience by the things which He suffered, the Hebrews have to "obey" Him in order to gain eternal salvation.
Hebrews says that if any "fall away" (from the doctrine of Christ: 6:1-2) then it will be impossible for them to gain their salvation back and they will be cursed and burned (Heb. 6:3-9). This is what 2 John 9, "Whosoever transgresseth, and abideth not in the doctrine of Christ, hath not God. He that abideth in the doctrine of Christ, he hath both the Father and the Son." Those that "fall away" from the doctrine of Christ and abide not in it, they lose their salvation.
The Hebrews had works and labors of love which they showed towards God's name and they ministered to the saints. They needed to shew this same diligence to the full assurance of hope unto the end, not being slothful, but followers of them who through faith and patience inherit the promises. (Heb. 6:10-12).
Hebrews 9:28 says that the Hebrews have to be LOOKING for the Second Advent in order to appear without sin unto salvation. That is doctrine for Daniel's 70th Week according to Matthew 24:42-51, 25:13. Believers in the Dispensation of Grace won't even see the Second Advent, we will already be in Heaven. But even for our rapture, we do not have to be looking for it in order to take part in it (1 Thes. 5:9-10). Also, in the Dispensation of Grace we are already "without sin" and have "salvation" (Rom. 4:7-8, 5:11, etc.). It is the believing Jews in Daniel's 70th Week that get their sins blotted out at the Second Advent, not us (Acts 3:19-21, Rom. 11:25-28, Matt. 19:28-29, Jer. 23:6, 33:8, etc.).
Hebrews 10:23-27 says that the Hebrews need to hold fast the profession of their faith without wavering, provoking one another to good works, as they see the day approaching (Day of the Lord). Why? Because if they sin wilfully after they received the knowledge of the truth, there is no more sacrifice for their sins. Only a "a certain fearful looking for of judgment and fiery indignation, which shall devour the adversaries".
Hebrews 10:28-31 says that the Hebrews that were sanctified will receive a "MUCH SORER PUNISHMENT" than being killed (fiery indignation, hell vs 27) if they trod underfoot the Son of God and count the blood of the covenant an unholy thing. God will take "vengeance" on them and judge them. That is not the Dispensation of Grace where we have "peace with God" and are not under His wrath (Rom. 5:1, 5:9, 1 Thes. 1:10, 5:9).
Hebrews 10:35-39 commands the Hebrews to cast not away their confidence, that they "need" patience after they have done the will of God in order to receive the promise. Verse 37 says that the Second Advent is at hand. Verses 37-38 plainly say that if the Hebrews "draw back" their faith then they have drawn back unto perdition and not believed to the saving of the soul.
Hebrews 12:14-17 says that the Hebrews have to follow peace with all men, and holiness, without which no man shall see the Lord. Looking diligently lest any man fail of the grace of God; lest any root of bitterness springing up trouble you, and thereby many be defiled; Lest there be any fornicator, or profane person. If you take that for what it says, the Hebrews who do not follow peace and holiness will not see God, they will fail of the grace of God and be defiled. They will be "rejected" as Esau was.
Hebrews 12:25 says that the Hebrews have to "refuse not him that speaketh. For if they escaped not who refused him that spake on earth, much more shall not we escape, if we turn away from him that speaketh from heaven". The Hebrews have to "have grace, whereby we may serve God acceptably with reverence and godly fear: For our God is a consuming fire." Obviously we under Grace should serve God acceptably, but we are not in danger of being consumed by fire.
Your second point is that "we find a new covenant" in the book of Hebrews. Exactly! That is one of the main reasons Mid-Acts Dispensationalists understand that it is written to Israel. The New Covenant with Israel as prophesied of in Jeremiah 31:31-36, 32:36-42, 33:1-18, Ezekiel 11:17-21, 36:12-38, 37:1-28, etc. is made with ISRAEL. It is done at the end of Daniel's 70th Week at the Second Advent, when God will pour out His Spirit on Israel and put His "LAW" in their heart. It includes believing Israel being restored to their land, rapture and resurrection to their land, receiving a new King, receiving atonement by the blood of Christ, and receiving the Holy Spirit with the Law in their hearts. And remember it is at the Second Advent when He takes away theirs sins and they receive the atonement as seen in those scriptures above as well as Matthew 19:28-29, Acts 3:19-21, Rom. 11:25-27, and scores of other passages.
This New Covenant is NOT made with the Gentiles. The people who receive the NEW Covenant are the same ones that had the OLD Covenant. Which is obvious by the plain statement, "I will make a new covenant with the house of Israel and with the house of Judah". "this is the covenant that I will make with the house of Israel after those days" (Hebrews 8:8-10). From the context of the passages listed above, it is clear that this New Covenant is not made until the end of Daniel's 70th Week when the Lord gathers Israel and sets them in their own land. Millennial context of the New Covenant is evidenced by the fact that the covenant states "they shall not teach every man his neighbour, and every man his brother, saying, Know the Lord: for all shall know me, from the least to the greatest". It is only in the Millennium when everyone will know the Lord, when He is physically here on Earth ruling from Jerusalem with the believing Jews and the remnant of Gentile nations comes up to worship Him (Isa. 2, Micah 4, Zech. 14, Isa. 66, etc). Nobody today keeps the New Covenant because #1 They are not Jews. #2 They don't keep the Law. #3 They are not in Israel. etc.
As for your arguments about the author wanting to be with the Hebrews shortly and wanting them to pray for him (13:18, 13:23-25), that is a straw man argument. No Mid-Acts Dispensationalist disputes the fact that Hebrews is a letter to historical people. We believe that Hebrews, as well as most of James-Revelation, were written between Acts 1-8 before the Dispensation of Grace was dispensed and when the Kingdom was being offered to Israel (Acts 1:6-8, 2:30, 3:19-26). These epistles were written to real, historical people. In particular they were written to the Hebrews under New Covenant doctrine because the "little flock" was going to get the Kingdom (Luke 1:32-33, 1:67-79, 12:32, Matt. 19:28-29, Acts 1:6, 2:30, 3:19-26). Of course, the mystery Dispensation of Grace has been interrupting that for the past 2,000 years.
Just because Hebrews-Revelation were books given to people historically does not mean that they are not prophetic in doctrine. The OT prophets were written historically to Israel years ago, but their doctrine is mostly prophetic.