The passage (see Hebrews 10:10-39) from which this verse is taken must be read as a whole in order to ever have a correct understanding of what is meant by this particular verse. It is necessary to capture the whole train of thought which the writer gave. Many have gone shipwreck in their interpretations of scripture because they take verses or parts of verses out of their proper context and try to build foundational truths upon them.
One of the greatest errors that has been entertained by men in their study of scripture is that of assuming that because something is commanded in the scriptures, that it is within the power of men to perform it. Conversely the thought is also an error when men assume that because something is warned against that it can actually occur.
The primary purpose of the giving of the written law to men was not to enable them to live happy lives by abiding by these commandments but rather to reveal to them their total inability as sinners to even begin to keep them or measure up to the righteousness which is demanded by them. Yet multitudes in all ages have in one fashion or another taught that men can earn the favor of GOD by a conscientious adherence to HIS precepts. Paul tells us that he once thought himself alive and well and a keeper of the law but when the power of the law (and its spiritual nature) was revealed to him, he was slain by it and caused to despair of any hope of keeping it. (see Romans 7:7-13)
A misunderstanding of the nature and purpose of the law is at the heart of the error of conditionalism. Conditionalism is the idea that men can merit the favor and blessings of GOD by a performance of the various duties which the children of GOD are exhorted to do. The other side of the coin is that they will forfeit the benefits and blessings of GOD if they fail to live up to these standards. This line of thought appeals to men and is a comforting sort of mindset to the religious man who would go about to establish his own righteousness.
Yet to the man, who is convinced of his own sin and innate depravity by the quickening work of the HOLY GHOST, compounded by the revelation of his own inability to meet these demands, the law appears a dreadful thing and one which drives him to CHRIST for mercy. And so the true purpose of the law is fulfilled.
The blessings and benefits which are visited upon the sons of GOD are bestowed upon them by promise and purchased and secured (or declared) by the work of CHRIST in the behalf of HIS elect children. (see Galatians 3:13-18) Because these blessings are granted to the children of GOD by promise then there is nothing that can be either earned by their obedience nor forfeited by their disobedience. “That no flesh should glory in his presence. But of him are ye in Christ Jesus, who of God is made unto us wisdom, and righteousness, and sanctification, and redemption: That, according as it is written, He that glorieth, let him glory in the Lord.” (1 Cor. 1:29-31)
So in order that we might have a clear understanding of what the writer of Hebrews had in mind it is needful to note that this passage begins with a promise; “By the which will we are sanctified through the offering of the body of Jesus Christ once for all.” (Heb 10:10) and ends with another, “But we are not of them who draw back unto perdition; but of them that believe to the saving of the soul.” (Heb 10:39)
The doctrine of the final perseverance of the saints is a glorious one and while it is predicated on the doctrine of the preservation of the saints, these two doctrines are not identical . The saints of GOD persevere because they are preserved. We must not confuse this order or we embrace a legalism which would overturn what I would call the “law (or principle) of necessity”. The law of necessity says that whatever GOD has predestined to occur must of necessity take place. This includes not just the major events that we might witness but all of the minor events that take place in order to produce the major ones.
If “we are his workmanship, created in Christ Jesus unto good works, which God hath before ordained that we should walk in them.” (Eph 2:10) then of necessity the children of GOD shall walk in good works. If he has ordained that “we must through much tribulation enter into the kingdom of God.” (Act 14:22) then you can rest assured that “all that will live godly in Christ Jesus shall suffer persecution.” (2Ti 3:12) These things must come to pass.
Now in order to understand what the writer means by: “if we sin willfully”; we must look to the context of the passage in order to determine what “sin” he is speaking of. It is obvious that he could not be speaking of any and all sin since John has clearly stated, “If we say that we have no sin, we deceive ourselves, and the truth is not in us.” (1John 1:8) Even as John goes on to say later in the same epistle, “Whosoever is born of God doth not commit sin; for his seed remaineth in him: and he cannot sin, because he is born of God.” (1John 3:9), so unless he is contradicting himself he cannot be speaking of any and all sin but rather a specific type of sin which is defined in that particular context (i.e. John’s first epistle) as being the “transgression of the law” which literally means a total disregard or despising of the law. The sons of GOD cannot despise nor disregard HIS law because they are born again by HIS SPIRIT and would be contrary to their own calling and HIS work in them. (see Philippians 2:13)
The “willful sin” of which the writer of Hebrews is here speaking is also defined in the context of the passage and is a disregard and disdain of the sacrifice of CHRIST as we see in Hebrews 10:29. This is the exact same “sin” that is defined in Hebrews 6:4-6 which is impossible to be repented of. It is clearly the rejection of CHRIST as a sin SUBSTITUTE. If a man should turn from CHRIST then he would have no grounds upon which to expect repentance, faith, or any sort of acceptance with the FATHER.
It is an impossibility that those, who are born again by the SPIRIT of GOD and caused to hear the voice of the SHEPHERD, should ever or could ever deny the very grounds upon which their whole HOPE rests. The power of the sons of GOD to stand and not fall is not in any wise an ability which they possess or exercise but rather is a gift bestowed upon them as HE keeps them from falling according to HIS purpose. (see 1 Peter 1:5; Jude 1:24) HE would have to deny HIS own purpose of REDEMPTION in order for one of them to ever perish. “My sheep hear my voice, and I know them, and they follow me: And I give unto them eternal life; and they shall never perish, neither shall any man pluck them out of my hand.” (Joh10:27-28)
The law of necessity ordains such admonitions as these found in Hebrews and in other parts of the scripture, as a means whereby to teach and exhort the sons of GOD to recognize their own continued reliance upon HIM until they reach their desired haven. Their pure minds are stirred up with thanksgiving at the remembrance of HIS faithfulness even as they are constantly made aware of their own fallibility and penchant for failure. They are ever taught the fact that HE is a consuming fire and that HE will by no means clear the guilty nor acquit the wicked. It is in these teachings that they are made to tremble in consideration of their own weakness and magnify HIS name because of the hope that HE has placed within their bosoms and the present working of HIS SPIRIT in them. “For Christ also hath once suffered for sins, the just for the unjust, that he might bring us to God” (1Pe 3:18)mam