Again ... not a book on why sin is okay, once or habitually. Sin is not okay.
Eternal security is a precarious topic. It is embraced by those who think a sinless lifestyle is impossible, and rejected by those who are not entirely realistic about the human disposition. The truth to it lies somewhere in the middle. Despite mistakes, salvation would never be yanked out from under us, but scripture is clear that it is something that can be lost under the right circumstances of disobedience, or walked away from, even by those who had the knowledge of the truth. But this is a topic for another thread.
Sanctification is a two part deal. Scripture relates it as both a thing that has been done to us, and a thing that we should pursue. We are cleaned and readied for service in holy matters by Christ (we are sanctified), but as individuals, it is our responsibility to continue perfecting ourselves for continued service in holy matters. Sanctify simply means to purify for use in holy service, just as the cup is purified. And we are instructed to purify ourselves.
However, this speaks to Christian living, not the institution of salvation and why it works. The final chapter of the book will deal with, "What Next?," and in the context of the question, sanctification will be given its due attention. But it's ancillary to the central idea of Christian living. If we live as Christians ought to live, sanctification will be part of the consequential result. Thus, sanctification and justification are concepts that are subordinate to a greater parent thought.
Now, not to mistakenly give you the impression that your comments on this stuff are unwanted or unappreciated, because neither is the case, but I was just looking for a little creativity so I could come up with a quality title. These doctrinal posts, which I am plenty tempted to engage in, are, unfortunately, off-topic. Rest assured, I'm well educated on the subject.
First, I agree that Sanctification is a two part thing. For Sanctification is indeed something that is done to us and Sanctification is also something we should pursue.
Second, while I am comforted that you are saying that this book is not a book on justifying how a believer can sin and still be saved, I am still concerned that you do not see the danger or darkness of Eternal Security or Once Saved Always Saved (Which I believe ignores sin on some level). For when a person knows that there are no dire consequences of their sin (in the afterlife), they are going to naturally do the wrong thing or they are not going to treat sin as seriously. In other words, if a person knows that their future sin is forgiven, there is no need to be overly concerned in living righteously or worrying too much about sin. It's either sin can separate you between God and man (Like with Adam and Eve and many others) or sin cannot separate you from God after being a believer. I see no middle ground taught within the Scriptures. One path leads to sin and the other to holiness. While believers can struggle with sin (with a remedy for those who are pure in heart to put their sin behind them), there is no teaching within the Scriptures that tells us that it is hard to lose your salvation. Remember, it only took one sin for Adam and Eve to fall out of fellowship with God. For Jesus gives warnings to the luke warm believer and it is not a favorable warning for them.
Verses you should consider meditating on in regards to Soteriology for your book are:
#1. Philippians 2:12
"Wherefore, my beloved, as ye have always obeyed, not as in my presence only, but now much more in my absence, work out your own salvation with fear and trembling."
#2. 2 Peter 1:5-10
5 "And beside this, giving all diligence, add to your faith virtue; and to virtue knowledge;
6 And to knowledge temperance; and to temperance patience; and to patience godliness;
7 And to godliness brotherly kindness; and to brotherly kindness charity.
8 For if these things be in you, and abound, they make you that ye shall neither be barren nor unfruitful in the knowledge of our Lord Jesus Christ.
9 But he that lacketh these things is blind, and cannot see afar off, and hath forgotten that he was purged from his old sins.
10 Wherefore the rather, brethren, give diligence to make your calling and election sure: for if ye do these things, ye shall never fall:"
#3. Luke 13:23-24
23 "Then said one unto him, Lord, are there few that be saved? And he said unto them,
24 Strive to enter in at the strait gate: for many, I say unto you, will seek to enter in, and shall not be able"
#4. 1 Peter 2:11
"Dearly beloved, I beseech you as strangers and pilgrims, abstain from fleshly lusts, which war against the soul;"
#5. Hebrews 4:11
"Let us labour therefore to enter into that rest, lest any man fall after the same example of unbelief"
#6. Hebrews 5:9
"And being made perfect, he became the source of eternal salvation to all who obey him"
#7. Galatians 6:7-9
7 "Be not deceived; God is not mocked: for whatsoever a man soweth, that shall he also reap.
8 For he that soweth to his flesh shall of the flesh reap corruption; but he that soweth to the Spirit shall of the Spirit reap life everlasting.
9 And let us not be weary in well doing: for in due season we shall reap, if we faint not."
#8. Isaiah 66:2
"For all those things hath mine hand made, and all those things have been, saith the Lord: but to this man will I look, even to him that is poor and of a contrite spirit, and trembleth at my word."
#9. Hebrews 4:1
"Let us therefore fear, lest, a promise being left us of entering into his rest, any of you should seem to come short of it"
#10.
Proverbs 13:4 ESV
"The soul of the sluggard craves and gets nothing, while the soul of the diligent is richly supplied."
#11.
Matthew 10:28 BLB
"And you should not be afraid of those killing the body but not being able to kill the soul. Indeed rather you should fear the
One being able to destroy both soul and body in Gehenna."
#12. Romans 11:22
"Behold therefore
the kindness and severity of God: severity indeed upon those having fallen, but kindness of God toward you, if you continue in the kindness; otherwise you also will be cut off"
#13. Hebrews 10:26
"For if we sin wilfully after that we have received the knowledge of the truth, there remaineth no more sacrifice for sins."
#14. Hebrews 10:28-29
28 "He that despised Moses' law died without mercy under two or three witnesses:
29 Of how much sorer punishment, suppose ye, shall he be thought worthy, who hath trodden under foot the Son of God, and hath counted the blood of the covenant, wherewith he was sanctified, an unholy thing, and hath done despite unto the Spirit of grace?"
#15. Hebrews 10:38
"Now the just shall live by faith: but if
any man draw back, my soul shall have no pleasure in him."
#16. 2 Corinthians 13:5
"Examine yourselves, whether ye be in the faith; prove your own selves. Know ye not your own selves, how that Jesus Christ is in you, except ye be reprobates?"
#17. 1 John 1:7
"But if we walk in the light, as he is in the light, we have fellowship one with another, and the blood of Jesus Christ his Son cleanseth us from all sin."
#18. 1 John 2:3-6
3 "And hereby we do know that we know him, if we keep his commandments.
4 He that saith, I know him, and keepeth not his commandments, is a liar, and the truth is not in him.
5 But whoso keepeth his word, in him verily is the love of God perfected: hereby know we that we are in him.
6 He that saith he abideth in him ought himself also so to walk, even as he walked."
#19. John 3:19-21
19 "And this is the condemnation, that light is come into the world, and men loved darkness rather than light, because their deeds were evil.
20 For every one that doeth evil hateth the light, neither cometh to the light, lest his deeds should be reproved."
#20. John 14:15
"If ye love me, keep my commandments"
#21. 1 John 3:7-8
7 "Little children, let no man deceive you: he that doeth righteousness is righteous, even as he is righteous.
8 He that committeth sin is of the devil; for the devil sinneth from the beginning. For this purpose the Son of God was manifested, that he might destroy the works of the devil."
#22. 1 John 2:29
"...ye know that every one that doeth righteousness is born of him."
#23. 1 John 3:10
"In this the children of God are manifest, and the children of the devil: whosoever doeth not righteousness is not of God, neither he that loveth not his brother."
#24. 1 John 3:15
"Whosoever hateth his brother is a murderer: and ye know that no murderer hath eternal life abiding in him."
#25. Matthew 6:15
"But if ye forgive not men their trespasses, neither will your Father forgive your trespasses"
#26. Matthew 5:28-30
28 "But I say unto you, That whosoever looketh on a woman to lust after her hath committed adultery with her already in his heart.
29 And if thy right eye offend thee, pluck it out, and cast
it from thee: for it is profitable for thee that one of thy members should perish, and not
that thy whole body should be cast into hell.
30 And if thy right hand offend thee, cut it off, and cast
it from thee: for it is profitable for thee that one of thy members should perish, and not
that thy whole body should be cast into hell."
#27. Revelation 21:8
"But the fearful, and unbelieving, and the abominable, and murderers, and whoremongers, and sorcerers, and idolaters, and all liars, shall have their part in the lake which burneth with fire and brimstone: which is the second death."
Side Note:
As for discussing a proper understanding of Soteriology, this is an important discussion to have if one desires to have a correct title for a book that is focused on a proper teaching of Salvation. So I do not see it as being off topic. The title should reflect a correct understanding of Salvation as taught within the Scriptures. If one does not have a correct understanding on the Salvation within the Scriptures, then the Title for their book will be misleading as to what the Scriptures really say.
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