Out of convenience for a system that corrupts salvation and sanctification, labels are applied and used towards professing believers that are in fact Scripturally describing unsaved people falsely pretending to belong to God. The four most common are “backslidden,” lukewarm,” “carnal,” and “unbelief.” The Bible describes all four clearly as lost, yet they are extremely frequently used to describe supposed Christians just not living right. This is so very common today, flooded throughout sermons and literature, among “evangelicals” and reformed Calvinists and Baptists alike, very few even bat an eye when they hear the terminology, taking it in as good Christian fodder, the pied piper piping and his faithful followers following (re: picture above). Its however not derived from exegesis but from twisting Gods Word.
Though every single neo-evangelical is guilty of this, especially the influential big eva heretics and false teachers who dominate the bookstores and air waves, another name comes to mind that should know better and that is David Cloud of Way of Life Ministries, who is guilty quite regularly of this. His articles and one year discipleship course, the four parts on Christian Growth and Victory, contain a fair amount of this Keswick currency. The error of this unscriptural theology, not only by fact of misusing Bible language and twisting scripture, is creating two-tiered Christianity that gives a false assurance to multitudes of false professing Christians, essentially making them two-fold children of hell. With that said, David Cloud is leaps and bounds above practically any single neo-evangelical by a million miles because he is actually a true born again believer and bold witness and defender of God's truth. But he is however wrong on this matter.
The use of Bible language reserved solely for the lost, towards people that are allegedly saved, most often reveals very serious salvation and sanctification issues, but not always.
“Carnal Christian,” “backsliding,” “lukewarm” and “unbelief,” are Keswick/higher life/revivalism currency to describe people that are actually unsaved and feigning faith, yet treated as saved. They are a convenient label given to people that profess to be Christian but live after their flesh and the world, qualifying them as “members” of a church and as “brothers” when they’re actually unsaved. To call this elusive category as saved is a dangerous lie invented by false teachers, and is eternally destructive to these deceived souls who should be shown from scripture their lost condition.
There’s ONLY two categories in the Bible, not three, and all people fit into one of the two. “Carnal,” “backslider,” “lukewarm,” “unbelief” are put into a third category that doesn’t exist. These are just lost people. That’s it. There are no in-betweeners in the Bible, no have-nots, and these terms are have-nots. Consider some examples amongst many of the two-only categories (many scripture references could be provided), further detailed in this article. You are either saved or lost, believer or unbeliever, saint or sinner, righteous or unrighteous, dead to sin or dead in sin, free or in bondage, born of the Spirit or born of the flesh, under grace or under law, just or unjust, on the narrow path or on broad path, in path of life or path of death, spiritual or natural, seeing or blind, wise or fool, blessed or cursed, uncondemned or condemned, in light or in darkness, fruitful or unfruitful, obedient or disobedient, serving God or serving self/mammon, wheat or tare, good tree or corrupt tree, abiding in Christ/God's Word or not abiding in Christ/God's Word, life built on rock or life built on sand, etc.
The Bible is loaded with this continual contrast between saved and unsaved or what we were before salvation and what we are after. There are only two categories. Nothing about the doctrine of salvation or its fruit lends any support to “backsliders” or “lukewarm” or “carnal Christians” or “unbelief” as being saved. Here is a brief look at these four misused words, which stem from and produce further false doctrine:
1. Backsliding. The term is found only in the OT. Essentially all 16 occasions the word or its derivates show up it refers to unsaved people and almost entirely to Israel as a lost nation: Pr 14:14; Jer 2:19; 3:6, 8, 11-12, 14, 20-22; 5:6; 8:5; 14:7; 31:22; 49:4; Hos 4:16; 11:7; 14:1-4. The NT is silent on it. Backsliding means to apostatize, “An apostate; one who falls from the faith and practice of religion (Webster’s 1828), and we know absolutely no apostate is saved (e.g. 2 Pet 2:17-22; Heb 3:7-4:11; 10:38-39). Never is backsliding used to describe a true believer in Scripture. Jer 7:23-24; 15:6 and Heb 10:38-39 specifically tell us those who go backwards are unsaved. They go backwards from the knowledge and light they have obtained, even as 2 Pet 2:20-22 warns, it would've been better if they had never received the knowledge concerning the Lord and Saviour Jesus Christ, then to turn from it and from the grace they are already received and meant to lead them to salvation (Ti 2:11), then to fall away (this is where falling away occurs, not from a truly saved position) and turn back to their vomit and mire like the dog and pig.
Here is an informative article as to why Saved People Don't Backslide - They Are Not Apostates,
2. Lukewarm. The term is given much ado even though it’s found only once in the Bible, in Rev 3, describing the pastor and majority of the Laodicean church as ones professing Christ but very plainly lost.
"And unto the angel of the church of the Laodiceans write; These things saith the Amen, the faithful and true witness, the beginning of the creation of God; [15) I know thy works, that thou art neither cold nor hot: I would thou wert cold or hot. [16] So then because thou art lukewarm, and neither cold nor hot, I will spue thee out of my mouth. [17] Because thou sayest, I am rich, and increased with goods, and have need of nothing; and knowest not that thou art wretched, and miserable, and poor, and blind, and naked: [18] I counsel thee to buy of me gold tried in the fire, that thou mayest be rich; and white raiment, that thou mayest be clothed, and that the shame of thy nakedness do not appear; and anoint thine eyes with eyesalve, that thou mayest see." (Rev 3:14-18)
Lukewarm is very obviously lost. Verses 17 and 18 is full of adjectives describing the "lukewarm" professing "believer." God doesn’t vomit His children out of His mouth (Rev 3:16) but chastises them in love (Rev 3:19; Heb 12:7-11; Pr 3:11-12). He does however spew out the false believer and teacher because they are pretending to be hot while actually cold, an admixture that creates a lukewarm and very dangerous estate. This is what we see in > 95% of “evangelical,” protestant and Baptist Christianity today. The text of Rev 3:14–18 clearly tells us lost is the estate of its beholder, and spiritually blind and deceived at that.
Breaking it down: those that are blind (v. 18) are always lost (v. 19; cf. Matt 13:15; Eph 4:18; Ac 26:18; 2 Cor 4:3-4; 1 Th. 5:4-10). Those that are naked (v. 18) are always lost because they are not clothed with the white raiment of salvation (v 19; cf. Rev 3:4-5; 4:4; 6:11; 7:9, 13-14; 16:15; 19:14). Those that think they are rich in this world (v. 18) are in fact lost (v. 19), their affections completely reversed, having never received the greatest gift that this life has to offer—eternal salvation through the Lord Jesus Christ, having never bought this greatest invaluable gift of salvation, not with money or gold but with their very lives by repenting and denying themselves and losing their lives for Christ and the gospel sake (read Is 55:1-7; Pr 23:23; Matt 10:39; 16:25; Mk 8:34-36; Lk 9:23-25; 17:33; Jn 12:25). The call to come and buy is very clear.
"Buy the truth, and sell it not; also wisdom, and instruction, and understanding." (Pr 23:23)
“Ho, every one that thirsteth, come ye to the waters, and he that hath no money; come ye, buy, and eat; yea, come, buy wine and milk without money and without price. . . . Incline your ear, and come unto me: hear, and your soul shall live; and I will make an everlasting covenant with you, even the sure mercies of David. . . . Seek ye the LORD while he may be found, call ye upon him while he is near: Let the wicked forsake his way, and the unrighteous man his thoughts: and let him return unto the LORD, and he will have mercy upon him; and to our God, for he will abundantly pardon.” (Is 55:1, 3, 6-7).
While Is 55:1-3 is the call to salvation, not only the Jew but also extended also to the Gentile (v. 5), and vv. 6-7 tells us how that salvation can be obtained. This is distinctly what Jn 6:35, 47-58 and other passages such as Jn 12:24-25; Mk 8:34-38; Matt 16:24-26; Lk 9:23-26, 57-62; and more, speak of. How can ye drink and eat, and buy without money or price? By seeking and calling upon the Lord while he is near and to be found, and then repenting, that is, losing or denying your life, forsaking all and turning from your wicked ways and thoughts and God will be merciful and abundantly pardon (Is 55:6-7).
This is what Jesus was referring to when He said “I counsel thee to buy of me gold tried in the fire, that thou mayest be rich,” (v. 18). These at Laodicea had not repented and forsaken all, and bought the pearl of great price or the field of hidden treasure (Matt 13). The rich young ruler is also an example of this (Mt 19; Mk 10; Lk 18). These things are all received at salvation: eyes that see, white raiment of righteousness, and riches of Christ including eternal life, all of which the lukewarm pastor and his majority church didn’t have. These weren’t “Christians” living in disobedience (all saved people live in habitual obedience, loving the Lord by keeping His words: Jn 14:23-24; 1 Jn 2:3-5), but lost people who had never been saved, while feigning faith and Christianity.
3. Carnal “Christians.” There is no such thing in Scripture. Its also a contradiction of terms. It is no more accurate than "Christian" rock music. The word "carnal" means lost. Unregenerate. Of the flesh and natural man. Like the rest of Scripture, Paul divides everyone into two categories, not three: natural or carnal (1 Cor 2:12a, 14; 3:1-3) and then spiritual (1 Cor 3:9-13, 15-16). Ignoring chapter and verse divisions, the context is extremely clear that the natural or carnal person is the exact same person: one that is lost (2 Pet 2:12; Ju 1:10), and this is who Paul contrasts the sinning Corinthians to in 1 Cor 3:1-3 (“as unto carnal . . . are ye not carnal, and walk as men?”) Paul likens the Corinthians to carnal people, questioning whether they were actually lost (carnal), walking as lost Gentiles. He had just divided them into two peoples: spiritual (saved) and natural (lost) (1 Cor 2:9-16). They were professing spiritual but behaving as natural. And many of them were unsaved, alluded to throughout the two epistles.
There was lost people in that church (1 Cor 5; 2 Cor 12:20-21; 13:5) but some involved in sin repented (2 Cor 7:9-11) but some did not (2 Cor 12:20-21). The carnal are lost professors made very clear by Rom 8:1-9, a clear contrast of lost and saved. In those passages we find that the lost walk/live after the flesh, are carnally minded, at enmity against God, under law of sin and death, cannot please God and without the indwelling Holy Spirit. The saved on the other hand walk after the Spirit, are spiritually minded and mind the things of the Spirit, are eternally freed from the law of sin and death by the law of the Spirit of life in Christ, fulfill the righteousness of the law, are in the way of life and peace, and have the indwelling Spirit. Neither Rom 8:1-9 or 1 Cor 3 are contrasting two types of Christians, but saved and unsaved.
Read here for more about The Class of Christian known as “Carnal Christian" and the Misinterpretation of 1 Corinthians 3:1-3 to Produce the Erroneous Teaching of "Carnal Christianity."
4. Unbelief. No saved person in Scripture is said to be in unbelief. Unbelief is always an inference to lost people. This is simple common sense prevailing: unbelief = unbeliever. The two words mean the exact same thing. Unbelief comes from an evil heart (Heb 3:12), which is not a saved heart. It is not a sin that saved people can even commit or live in, for the just live by faith (Hab 2:4; Rom 1:16-17; Gal 3:11; Heb 10:38) and by the faith of Jesus, lest ones faith could be lost, which it can’t (losing salvation is a damnable heresy). Seven times in Heb 3:7-4:11 we read of the children of Israel in unbelief during their wilderness sojourn (and actually for all their history), that they were unbelievers, which is confirmed by plenty of evidence throughout the Bible (e.g. Ps 78; 106; 2 Cor 3:13-16).
All the words in the underlying Greek, the adjective "apeitheis,” the nouns "apeitheia" and “apistia,” and the verb "apeitheo,” translated as unbelief in the KJV (also translated as disobedience) refer to the unregenerate, the lost. No NT text states or implies that believers are in unbelief. The same applies to the OT. The Old Covenant was not one of works but of faith. Salvation has never changed. Abraham is the father of our faith, and if we believe like Abraham, we can also be justified (saved) like him (Gen 15:1-6; Rom 4:1-8, 18-25). Nowhere is the demand of faith treated as a novelty of the new covenant, or is a distinction drawn between the faith of the two covenants; everywhere the sense of continuity is prominent (e.g. Jn 5:24, 46; 12:38, 39, 44; 1 Pet 2:6), and the “hearing of faith” (Gal 3:2, 5; Rom 10:16-21) is conceived as essentially one in both dispensations, under both of which the law reigns that “the just shall live by his faith” (Hab 2:4; Rom 1:17; Ga 3:11; Heb 10:38). Heb 11 speaks of this and Heb 11:6 speaks of the faith required, whether OT or NT, to be saved. Those that come to God and believe that He is, and a rewarder of them that diligently seek Him are rewarded with salvation and eternal life, which is what Heb 11:6 is teaching. All the saved live by faith (Heb 11) and no saved person does not.
Read here for further info as to why "Unbelief" is Only a Characteristic of Unsaved People, Not the Saved."
Concluding, there are only two categories of man in the Bible, NOT three. God's Word is truth. The truth matters, right down to jot and tittle. Gods truth, His Word, is greater than His own name (Ps 138:2). The Bible is plain and perspicuous (Pr 8:8-9) to the saved (Pr 22:20-21), when scripture is interpreted by context, grammatically, compared with scripture and rightly divided. That is what God wants, since He does not, and cannot, and will not teach or lead contrary to His truth. Interpreting scripture correctly is more important than anything you will ever do, because out of that comes belief, doctrine, and sound doctrine, or if not, the opposite, false doctrine. Gods Spirit only teaches and leads in truth (1 Jn 2:20-21, 27) and He can only teach truth when scripture is rightly interpreted and taught.
The Holy Spirit never sits at the table of error regardless of good intentions. There is a very great danger in not interpreting scripture rightly, besides dishonouring to God. False doctrine, leaven, is created from even just a little misinterpretation (Gal 5:9). Its so strongly reproved in scripture, those who do it willfully are warned of being false teachers (2 Pet 1:16-21 and 3:16-17; 1 Tim 6:3-5; 2 Jn 1:9). To arrive at the false conclusion that “Carnal Christian,” “backsliding,” “lukewarm” and “unbelief,” apply to true Christians, much Scripture must be misused and abused. Pr 13:13 warns,
“Whoso despiseth the word shall be destroyed: but he that feareth the commandment shall be rewarded.”