Can a child of God sin so as to be lost? Can one fall from grace? Does the possibility of apostasy exist? Some would answer "no" to all of these questions. They believe there is no security for the believer if the doctrine of "once saved, always saved" is not true. They contend earnestly for "the impossibility of apostasy." I believe, however, that there are passages that plainly teach that a child of God may sin so as to be lost. Yet, there is still security for the believer.
The scriptures teach that a child of God may sin so as to be lost in as much as the scriptures teach that one who has believed can:
1) Depart from the faith;
"Now the Spirit speaketh expressly, that in the latter times some shall depart from the faith, giving heed to seducing spirits, and doctrines of devils." (1Timothy 4:1)
2) Have an evil heart of unbelief and depart from the living God;
"Take heed, brethren, lest there be in any of you an evil heart of unbelief, in departing from the living God." (Hebrews 3:12)
3) Crucify Jesus afresh, fall away, and it be impossible to renew him unto repentance;
"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, And have tasted the good word of God, and the powers of the world to come, 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." (Hebrews 6:4-6)
4) Err from the truth and his soul be dead until and unless he is converted from his error;
"Brethren, if any of you do err from the truth, and one convert him; Let him know, that he which converteth the sinner from the error of his way shall save a soul from death, and shall hide a multitude of sins." (James 5:19-20)
5) Be overcome by the sins of the world and be worse off than he was before he first escaped the pollution, or sins, of the world through the knowledge of Christ;"
"For if after they have escaped the pollutions of the world through the knowledge of the Lord and Saviour Jesus Christ, they are again entangled therein, and overcome, the latter end is worse with them than the beginning. For it had been better for them not to have known the way of righteousness, than, after they have known it, to turn from the holy commandment delivered unto them." (2 Peter 2:20,21)
6) Have one's name blotted out of the book of life;
"Thou hast a few names even in Sardis which have not defiled their garments; and they shall walk with me in white: for they are worthy. He that overcometh, the same shall be clothed in white raiment; and I will not blot out his name out of the book of life, but I will confess his name before my Father, and before his angels." (Revelation 3:4-5)
Because of these poignant scriptures and others like them, one writer asked:
Does Anybody Believe:A child of God can deny the faith (1 Tim. 5:8), cast off his faith (1 Tim. 5:12), err concerning the faith (1 Tim. 6:10), turn aside from the faith, depart from the faith (1 Tim .4:1), have his faith shipwrecked (1 Tim. 1:19), have his faith overthrown (2 Tim. 2:18) and still be saved!!?
What if, in addition to the above, he: denies the Lord (2 Pet. 2:1), departs from God (Heb. 3:12), and does despite unto the Spirit (Heb. 12:29). Will he still be saved?
But he goes further, and: Fails (falls short, H.H.) of the grace (Heb. 12:15), comes short of the promise (Heb. 4:1), falls from his steadfastness (Matt. 10:22), turns aside after Satan (1 Tim. 5:15), falls into condemnation (1 Tim. 3:6), becomes worse than an infidel (1 Tim. 5:8), and falls in unbelief (Heb. 4:11). Won't this man be lost?
(taken from Gospel Anchor, article written by A.C. Grider, Vol.1, no. 7, scriptures added)
Those who believe in the impossibility of apostasy understand passages like "He that heareth my word, and believeth on him that sent me, hath everlasting life, and shall not come into condemnation; but is passed from death unto life" (John 5:24) to teach that believers possess eternal life now and that they cannot return to condemnation. While it is true that believers now have the promise of eternal life and that believers are not condemned now, one can lose his faith and become condemned. One example of such is a particular group of younger widows. Paul wrote, " But the younger widows refuse: for when they have begun to wax wanton against Christ, they will marry; Having damnation, because they have cast off their first faith" (1 Timothy 5:11,12). Jesus said, "He that believeth on the Son hath everlasting life: and he that believeth not the Son shall not see life; but the wrath of God abideth on him" (John 3:36). If the believer cannot lose his faith and be condemned, the unbeliever cannot become a believer and receive life. We know the latter is not true. We have the hope of eternal life as long as we believe; we are condemned when we disbelieve! No Bible passage teaches the impossibility of apostasy.
Some who believe that it is impossible to fall from grace think that if the saved can sin so as to be lost, there can be no such thing as eternal life. They ask, "How can it be eternal life if you can lose it?" To say that we have eternal life and that to lose it makes it less than eternal is like saying eternal damnation is less than eternal because an unbeliever becomes a believer and is no longer eternally condemned. We possess eternal life now only as a conditional promise. Eternal life is our hope (Titus1:2); but a person does not hope for that which he already has (Romans 8:24, 25). Hence, we have eternal life only in promise. Peter affirms this truth by declaring our salvation will be revealed at the revelation of Jesus Christ (1 Peter 1:13). If we believe and keep believing, we will receive eternal life at the resurrection when Christ comes again (1 Corinthians 15:51-54).
Some who believe once saved always saved have asked, "If one becomes a child of God, is he not always a child of God?" They argue: "My sons will always be my sons no matter what they do; I may be displeased with them and may even punish them, but they are still my sons. Will God do less for His children?" First, we must be careful about asserting truths from analogies that we have made. While believers are described as children of God, we are His spiritual family, not children by fleshly procreation. While there may be some similarities between our families and God's family, there may be some dissimilarity, too. For instance, in the scriptures we are born into the kingdom (John 3:3,5), but we are also described as adopted sons of God (Romans 8:15). How can it be both? And how can we assert that once we are children of God we will always be children of God, if the scriptures do not so teach? Secondly, even if we accept the analogy, one may disinherit a son, and the son is heir to nothing. God can certainly choose to make us heirs of nothing. We would then, according to the analogy, be children in name, but not heirs of eternal life. We would have sinned so as to be lost.
The security of the believer does not rest in the false doctrine of once saved always saved, or the impossibility of apostasy, or the impossibility of falling from grace. The security of the believer rests in walking after the Spirit and not after the flesh. Paul said, "There is therefore now no condemnation to them which are in Christ Jesus, who walk not after the flesh, but after the Spirit" (Romans 8:1). John said, "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...If we confess our sins, He is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness" (1 John 1:7,9). The believer is secure in Christ, but only when he walks according to the Spirit, or walks in the light.