Many are they who will argue that Hebrews 10:26-31 is not a passage teaching apostasy. They believe in OSAS (once saved always saved), the eternal security of the believer, and the perseverance of the saints. They will argue that the author is either a) warning those who aren’t true believers, or b) issuing a warning that God will use as a means to perseverance for the saints. The favorite verse used to prove such a view is Hebrews 10:39, “But we are not of those who shrink back and are destroyed, but of those who have faith and preserve their souls.”
What intrigues me is the lengths we will go to to make our pre-existing paradigm work. The author is addressing Jewish Christians, he refers to them as those who have “received the knowledge of the truth” (v. 26) and were “sanctified” (v. 29).
It seems to me that they are Christians who can fall away. It seems to me that the author is not pitting genuine Christians against ingenuous Christians, but those “who shrink back” against those who “have faith and preserve their souls” (v. 39). In other words, he is pitting those genuine Christians who will fall away against those who will persevere.
To counter by saying that he is addressing believers and he is giving them a warning that God will use as a means for their perseverance–in other words, he is warning them against something that can’t happen, but for the sake of it encouraging them to persevere, which they will do anyway–is as silly as a traveler coming across a “Beware of Cliff” sign in Kansas. This is the analogy Douglas Wilson uses, and it is a poignant one.
The statement the author makes in verse 39 is not to undermine his entire argument made in verses 26-31, but to encourage them in the hope that they are in fact faithful believers who preserve their souls. And how do we do this? By looking to Jesus, not by morbid introspection, not by worrying about whether we are elect or not, not by questioning our salvation, but by trusting Jesus.