For it is impossible, in the case of those who have once been enlightened, who have tasted the heavenly gift, and have shared in the Holy Spirit, and have tasted the goodness of the word of God and the powers of the age to come, and then have fallen away, to restore them again to repentance, since they are crucifying once again the Son of God to their own harm and holding him up to contempt (Hebrews 6:4-6 ESV).
Taken by itself, this seems to suggest that salvation can be revoked if we stop believing before we die. But if salvation couldn’t save us from our sin, then it would not be a salvation from sin. As we will hopefully see, the whole context of the book of Hebrews seems to preclude the interpretation that we are able to lose salvation. Is it really a warning to believers? Or to those who merely “taste tested” Christianity? We know the author’s readers include some that have neglected to believe the gospel, because he concludes the introduction to his book (really a sermon) with: Therefore we must pay much closer attention to what we have heard, lest we drift away from it . . . how shall we escape if we neglect such a great salvation? It was declared at first by the Lord, and it was attested to us by those who heard. . . (Heb 2:1-3)
Throughout the sermon, the author repeats this need to pay attention to testimony and thus endure in faith, not to make the point that one can lose their salvation, but to warn unbelievers who are within the church. For we have come to share in Christ, if indeed we hold our original confidence firm to the end (Heb 3:14. cf 3:18-19; 4:11). He defines faith as that which endures till death. Then, he comforts those who really do believe, saying, “Though we speak in this way, yet in your case, beloved, we feel sure of better things—things that belong to salvation. . . . And we desire each one of you to show the same earnestness to have the full assurance of hope until the end, so that you may not be sluggish, but imitators of those who through faith and patience inherit the promises (Heb 6:9, 11-12; also 10:39).
The author argues that Jesus died on the cross “once for all” our sins, “thus securing an eternal salvation” (9:12, 26) rather than a potentially temporary one. “Consequently, he is able to save to the uttermost those who draw near to God through him, since he always lives to make intercession for them” (7:25). “Let us then with confidence draw near to the throne of grace, that we may receive mercy” (4:16) For he says to those who believe to the end, “I will never leave you nor forsake you.” (13:5)