IMO, we should focus on the role our free will plays in our salvation.
Our covenant with God is quite different than
the old covenant, which is obsolete now.
(Not to say that free will wasn't/isn't important in both.)
Okay let's look at our free will, Hebrews 6 verse 4 we see "It is impossible for those who were once enlightened..."
How were we enlightened? If it means we have been saved then let's look at a few verses to help in our eternal security.
1. Romans 8:1 There is therefore now no condemnation to them which are in Christ Jesus, who walk not after the flesh, but after the Spirit.
2. Romans 8:33 Who shall lay any thing to the charge of God's elect? It is God that justifieth.
3. Romans 8:34-39
34 Who is he that condemneth? It is Christ that died, yea rather, that is risen again, who is even at the right hand of God, who also maketh intercession for us.
35 Who shall separate us from the love of Christ? shall tribulation, or distress, or persecution, or famine, or nakedness, or peril, or sword?
36 As it is written, For thy sake we are killed all the day long; we are accounted as sheep for the slaughter.
37 Nay, in all these things we are more than conquerors through him that loved us.
38 For I am persuaded, that neither death, nor life, nor angels, nor principalities, nor powers, nor things present, nor things to come,
39 Nor height, nor depth, nor any other creature, shall be able to separate us from the love of God, which is in Christ Jesus our Lord.
Romans 8:38 & 39 are the key passages,
38 For I am persuaded, that neither death, nor life, nor angels, nor principalities, nor powers, nor things present, nor things to come,
39 Nor height, nor depth, nor any other creature,
shall be able to separate us from the love of God, which is in Christ Jesus our Lord.
So that states nothing can separate us from the Love fo God.
Now let's look at a man in gross sin according the Scripture who Paul condemned and what was to happen.
1 Corinthians 5:1-5,
1 It is reported commonly that there is fornication among you, and such fornication as is not so much as named among the Gentiles, that one should have his father's wife.
2 And ye are puffed up, and have not rather mourned, that he that hath done this deed might be taken away from among you.
3 For I verily, as absent in body, but present in spirit, have judged already, as though I were present, concerning him that hath so done this deed,
4 In the name of our Lord Jesus Christ, when ye are gathered together, and my spirit, with the power of our Lord Jesus Christ,
5 To deliver such an one unto Satan for the destruction of the flesh, that the spirit may be saved in the day of the Lord Jesus.
Now this man is said to be in gross sin and what did Paul say would happen if he remained? He would be turned over to satan for destruction, notice not of his soul, but his flesh. In other words satan would be allowed to take this believer involved in gross and destroy his body and it says if that occurred and he died, then his "spirit may be saved in the day of the Lord Jesus." He kept his salvation.
Then we see too 1 Timothy 1:20 "Of whom is Hymenaeus and Alexander; whom I have delivered unto Satan, that they may learn not to blaspheme."
Two believers guilty of Blaspheme turned over to satan in order to learn not to blaspheme.
The believer in gross sin is subject to the sin unto death.
Now as for Hebrews 6:
"4 For it is impossible for those who were once enlightened, and have tasted of the heavenly gift, and were made partakers of the Holy Ghost,
5 And have tasted the good word of God, and the powers of the world to come,
6 If they shall fall away, to renew them again unto repentance; seeing they crucify to themselves the Son of God afresh, and put him to an open shame."
How come it is impossible to renew them to repentence, that to bring them to salvation. Well they have already been saved and since they remain saved even walking in sin they have no need of salvation, but they have every turning from sin and walking in the Spirit who is indwelling them. What did Paul say about this, well he gave every believer a command,
Ephesian 5:18 "And be not drunk with wine, wherein is excess; but be
filled with the Spirit;"
How can we lose the filling by being drunk with sin, the point is wine controls us just as sin controls us, therefore we are to allow the Spirit to Control our lives and not sin.
That is where 1 John 1:9 comes into effect, "If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness." If maybe will confess and maybe we won't but we will allow one or the other to control. That is every believer must choose to live for Christ or allow the flesh to control their lives. If they remain in a sinful state as believers then God will turn them over to satan for destruction of the flesh but the spirit will be saved. Jesus said this about the eternal security of believers,
John 10:27-29,
27 "My sheep hear my voice, and I know them, and they follow me:
28 And I give unto them eternal life; and they shall never perish, neither shall any man pluck them out of my hand.
29 My Father, which gave them me, is greater than all; and no man is able to pluck them out of my Father's hand"
So who can remove a believer from the hand of Christ or the Father, Jesus not one person and that includes the believer. We are eternally saved when we truly receive Christ. Most believers will not live a life of sin, but we see Paul give three such examples.
Now what of the man in 1 Corinthians 5, what happened to him?
We see 2 Corinthians 7:8-13
8 "For though I made you sorry with a letter, I do not repent, though I did repent: for I perceive that the same epistle hath made you sorry, though it were but for a season.
9 Now I rejoice, not that ye were made sorry, but that ye sorrowed to repentance: for ye were made sorry after a godly manner, that ye might receive damage by us in nothing.
10 For godly sorrow worketh repentance to salvation not to be repented of: but the sorrow of the world worketh death.
11 For behold this selfsame thing, that ye sorrowed after a godly sort, what carefulness it wrought in you, yea, what clearing of yourselves, yea, what indignation, yea, what fear, yea, what vehement desire, yea, what zeal, yea, what revenge! In all things ye have approved yourselves to be clear in this matter.
12 Wherefore, though I wrote unto you, I did it not for his cause that had done the wrong, nor for his cause that suffered wrong, but that our care for you in the sight of God might appear unto you.
13 Therefore we were comforted in your comfort: yea, and exceedingly the more joyed we for the joy of Titus, because his spirit was refreshed by you all."
They repented of their carnality and the man repented of his sin and was restored. He didn't lose his salvation as Paul said he wouldn't but when the church acted with discipline toward the sinning man and at the same time repented of the glorying over the situation. All were in a state of carnality for Paul said,
1 Corinthians 3:1-3,
1 "And I, brethren, could not speak unto you as unto spiritual, but as unto carnal, even as unto babes in Christ.
2 I have fed you with milk, and not with meat: for hitherto ye were not able to bear it, neither yet now are ye able.
3 For ye are yet carnal: for whereas there is among you envying, and strife, and divisions, are ye not carnal, and walk as men?"
They were full of sin in the church and amoung themselves and were glorying and puffed up about the man commiting such gross sin. But when Paul condemned it they repented, but had that man not repented, he would have been turned over to satan, by God, for destruction of the flesh that the spirit might be saved. The hebrew passages it is impossible because a person who is saved remains saved, cannot be brought back to repentance that salvation because they remain saved.