Hebrews 3:16

He wishes to show that all who went out through Moses perished because of their unbelief, so that these might fear all the more since they were in a similar situation to those against whom he was making the argument.

For some, having heard the promises of God, just as we hear them, provoked God to anger through unbelief. For He desires to save them just as He saves those who have heard, and they are of no benefit from merely hearing the promise. Thus, he says, you also will not be fulfilled if you have only heard the preaching, unless you also believe. And that there is a need for faith, from those who heard long ago, but because they did not believe, they perished, is confirmed by the word. For just as it was not sufficient for those to be deemed worthy of the voice of God, but having not believed they perished, so it will not be sufficient for you either to become hearers of faith, unless you also believe sincerely. Moreover, these thought that it was enough to have self-sufficiency from merely having heard the preaching. For this also indicates, in saying, "For we are also evangelized," just as they were. "For some, having heard, provoked, but not all who came out of Egypt." If indeed Caleb and Joshua were not unbelievers, they also entered the land of promise.

"For some when they had heard did provoke, howbeit not all that came out of Egypt by Moses: And with whom was He grieved forty years? Was it not with them that had sinned, whose carcasses fell in the wilderness? And to whom sware He that they should not enter into His rest, but to them that believed not? So we see, that they could not enter in because of unbelief." After again repeating the testimony, he adds also the question, which makes the argument clear. For he said (he repeats), "To-day if ye hear His voice, harden not your hearts, as in the provocation." Of whom does he speak (he says) as having been hardened? Of whom as not believing? Is it not of the Jews? Now what he says is to this effect. They also heard, as we hear: but no profit came to them. Do not suppose then that by "hearing" what is proclaimed ye will be profited; seeing that they also heard, but derived no benefit because they did not believe. Caleb then and Joshua, because they agreed not with those who did not believe, escaped the vengeance that was sent forth against them. And see how admirably he said, not, They did not agree, but, "they were not mixed" - that is, they stood apart, but not factiously when all the others had one and the same mind. Here it seems to me that a faction too is hinted at.