Does Heb. 6: 4–8 suggest that Christians can fall away and be eternally lost?
As ever, particular verses must be read, not only in the immediate context of the chapter, but also against the background of the book itself. Hebrews was written to Jewish disciples who had accepted Jesus as their Messiah but, as Heb. 6: 1–12, 10: 23–31 and 12: 25–29 show, were in danger of giving up Christ and going back to Judaism. At best the Hebrews were spiritually immature: “For when for the time ye ought to be teachers, ye have again need that [one] should teach you what [are] the elements of the beginning of the oracles of God” (Heb. 5: 12). They were babes (see v13), held back by the Judaism in which they had been nurtured, but should have been “full–grown men” (v14). Thus the exhortation is “let us go on [to what belongs] to full growth” (Heb. 6: 1). To do that they must leave “the word of the beginning of the Christ” (v1). What is that? Paul had warned them about neglecting so great a salvation that “had its commencement in being spoken [of] by the Lord” (Heb. 2: 3). This was hardly the Gospel of 1 Cor. 15: 1–8 for Christ had not then died. The prime thought of salvation here is “the habitable world which is to come” (Heb. 2: 5) when all will be subjected to Christ (see v8) in the Kingdom, Israel saved from her enemies and Satan bound (see Rev. 20: 2). It is this “of which we speak” (Heb. 2: 5). Paul says that this salvation “has been confirmed to us by those who have heard” (v3), that is the twelve and others—but not Paul. God Himself also confirmed this testimony in the book of Acts “both by signs and wonders, and various acts of power, and distributions of [the] Holy Spirit,” (v4). These were the credentials of the Kingdom of God (see Matt. 10: 5–8; 12: 28). This testimony the Hebrews appeared to have accepted, but they needed to go on from the “word of the beginning of the Christ” (Heb. 6: 1). They were in great danger of not only slipping away, but of falling away and turning away (see Heb. 2: 1; 6: 6; 12: 25). It was true that “now”, in contrast to the time of the kingdom, “we see not yet all things subjected to him”, as Son of Man on earth, but, as the apostle reminds these Jewish believers, faith sees “Jesus … crowned with glory and honour” (Heb. 2: 8, 9). Instead of going back to Judaism, they needed to go on into the fullness of Christianity. There was no need to lay the foundations again (see Heb. 6: 1) for all the six elements listed in vs1, 2, including resurrection, were taught in Judaism and known by Jewish disciples. Paul urged these Jewish brethren to leave these basic elements and to “go on [to what belongs] to full growth” (v1). This brings us to the verses in question.
While the apostle is persuaded “better things, and connected with salvation” (v9) of these Hebrews, and which he provides some evidence for in v10, he nonetheless feels bound to include the solemn warning of vs 4–8. This warning is in the abstract. He does not use we or you but those: “For it is impossible to renew again to repentance those …” (v4). Five external privileges and blessings are then given, none of which guarantees faith and spiritual life in those thus blessed. They had been “enlightened” (v4). Divine light had shone upon them—they had understood—but there is no thought that the light had shone in their hearts (see 2 Cor. 4: 6). They had tasted both “heavenly gift” and “the good word of God”, but taste is not consumption. When the Lord was offered a stupefying drink, He tasted it but did not drink it (see Matt. 27: 34). They had been made “partakers of [the] Holy Spirit” (Heb. 6: 4) but partaking is not the indwelling of the Spirit of God (see 1 Cor. 3: 16)—the Greek word used for partakers never goes beyond external association. Finally, they had experienced the “works of power of [the] age to come” (Heb. 6: 5), powers that belonged to the establishment of the Kingdom of God upon the earth. All these external blessings, like the rain on the earth (see Heb. 6: 7, 8), were no guarantee of spiritual fruit.
Now to the opening clause of v4: “For it is impossible to renew again to repentance those once enlightened … and have fallen away” (vs 4, 6). Nowhere does it say that those thus described had ever repented. The preposition to in “to repentance” always has the idea in Greek of direction and motion towards a point—in this case repentance, as in “the goodness of God leads thee to repentance” (Rom. 2: 4). God’s goodness had certainly brought the Hebrews to the very threshold of repentance—but had they crossed it? What had been used to renew them to that point? The five external blessings listed in Heb. 6: 4, 5. Why was it impossible to renew them again? Because God had expended everything that was in his testimonial treasury. There was nothing left. Hence renewal again was impossible.