I think Hebrews 6:4-8 is not talking about getting unsaved or saved. But it is talking about saved and unsaved people. Look at the verse from a Hebrew perspective. When Peter told the crowd how to get from where they were to God he said; 38Peter replied, "Repent and be baptized, every one of you, in the name of Jesus Christ for the forgiveness of your sins. And you will receive the gift of the Holy Spirit.
Repentance then was like an altar call. When a Jew needed to get right with God [OT] what did he do? He repented AND he offered a sacrifice. How many times? As many times as needed, yearly for sure during the feast of the Atonement, but daily the priests offered sacrifices for the people's sins.
The idea in Hebrews is the superiority of Jesus and the new way over the old way. But as we see with Paul's wranglings with those of the 'circumcision', many Jews and understandly so were steeped in OT practices and insisted on continuing in them and getting others [Gentile believers] to do so as well.
So we see from a Jewish perspective that repentance and sacrifice after one sinned was the way to get right with God again. Along comes Jesus. These Jews know Jesus, they have been enlightened, they have tasted the heavenly gift, they have shared in the Holy Spirit, and they have tasted in the goodness of God and the powers of the coming age. They are saved. But like you and me, they stumble, they are not yet perfect, they sin.
How does a good Jew get right with God? Repentance and sacrifice. But what about a 1st century believer-in-Jesus Jew? No problem, they just get saved again! Since Jesus is their sacrifice they attempt to renew themselves to repentance [get right with God] by getting resaved and in a sense resacrificing Jesus. Which is impossible to do. It puts Christ to open shame seeing how His one death didn't 'save' them 'enough' the first time.
Sin which is works done not in faith bear no fruit. Those works get burnt. The warning of 7-8 is that continous sinning shows you are not of the Lord. But the writer is confident that these are not like that, that they have the foreordained works of faith that does produce fruit.
It is impossible for saved people to resacrifice Christ just because they have sinned. But those who produce only thorns and thistles show that they were never of Christ.
In the one sense he affirms grace, that Jesus indeed has paid for all of our sins [so there is no need to get resaved] but on the other hand he is telling them that if they think that is a license to sin, they better think again.
He continues to expound the point of the greatness of the New Covenant and the sacrifice of Jesus. Hebrews 7 23Now there have been many of those priests, since death prevented them from continuing in office; 24but because Jesus lives forever, he has a permanent priesthood. 25Therefore he is able to save completely[3] those who come to God through him, because he always lives to intercede for them. 26Such a high priest meets our need--one who is holy, blameless, pure, set apart from sinners, exalted above the heavens. 27Unlike the other high priests, he does not need to offer sacrifices day after day, first for his own sins, and then for the sins of the people. He sacrificed for their sins once for all when he offered himself. 28For the law appoints as high priests men who are weak; but the oath, which came after the law, appointed the Son, who has been made perfect forever.
Once for all he tells them. One sacrifice for all their sins. He gives them more, Hebrews 8:
7For if there had been nothing wrong with that first covenant, no place would have been sought for another. 8But God found fault with the people and said : "The time is coming, declares the Lord, when I will make a new covenant with the house of Israel and with the house of Judah. 9It will not be like the covenant I made with their forefathers when I took them by the hand to lead them out of Egypt, because they did not remain faithful to my covenant, and I turned away from them, declares the Lord. ... 10This is the covenant I will make with the house of Israel after that time, declares the Lord. .... 12For I will forgive their wickedness and will remember their sins no more."
Their old way depended on their faithfulness which like us falls short. But the new way does not depend on our faithfulness but God will forgive us our wickedness and remember not our sins anymore. There is no need to keep getting 'saved' or repenting to get right with God salvationally.
In chapter 9 he tells them more of the superiority of Christ and...
24For Christ did not enter a man-made sanctuary that was only a copy of the true one; he entered heaven itself, now to appear for us in God's presence. 25Nor did he enter heaven to offer himself again and again, the way the high priest enters the Most Holy Place every year with blood that is not his own. 26Then Christ would have had to suffer many times since the creation of the world. But now he has appeared once for all at the end of the ages to do away with sin by the sacrifice of himself. 27Just as man is destined to die once, and after that to face judgment, 28so Christ was sacrificed once to take away the sins of many people; and he will appear a second time, not to bear sin, but to bring salvation to those who are waiting for him.
Not content with those proofs of the greatness of Jesus, he hammers it home again in chapter 10 ... 11Day after day every priest stands and performs his religious duties; again and again he offers the same sacrifices, which can never take away sins. 12But when this priest had offered for all time one sacrifice for sins, he sat down at the right hand of God. 13Since that time he waits for his enemies to be made his footstool, 14because by one sacrifice he has made perfect forever those who are being made holy
He then reiterates the New Covenant and tells us... 17Then he adds: "Their sins and lawless acts I will remember no more."[3] 18And where these have been forgiven, there is no longer any sacrifice for sin. 19Therefore, brothers, since we have confidence to enter the Most Holy Place by the blood of Jesus, 20by a new and living way opened for us through the curtain, that is, his body, 21and since we have a great priest over the house of God, 22let us draw near to God with a sincere heart in full assurance of faith, having our hearts sprinkled to cleanse us from a guilty conscience and having our bodies washed with pure water.
But to reiterate the warning in 6:8 he tells them: 26If we deliberately keep on sinning after we have received the knowledge of the truth, no sacrifice for sins is left, 27but only a fearful expectation of judgment and of raging fire that will consume the enemies of God. 28Anyone who rejected the law of Moses died without mercy on the testimony of two or three witnesses. 29How much more severely do you think a man deserves to be punished who has trampled the Son of God under foot, who has treated as an unholy thing the blood of the covenant that sanctified him, and who has insulted the Spirit of grace? 30For we know him who said, "It is mine to avenge; I will repay," and again, "The Lord will judge his people." 31It is a dreadful thing to fall into the hands of the living God.
But before the end of the chapter, he is again reassuring them that "we are not of them who shrink back and are destroyed, but of those who believe and are saved."
He hits the Old C everyway he can to show the superiority of the new way. He then goes on [in chap 11] to show the continuity of faith then and now. He showed them the depth of salvation in Christ, the utter completeness of it. 1Therefore let us leave the elementary teachings about Christ and go on to maturity, not laying again the foundation of repentance from acts that lead to death,[1] and of faith in God, 2instruction about baptisms, the laying on of hands, the resurrection of the dead, and eternal judgment. 3And God permitting, we will do so. And i think God did permit it.
