2 Kings

Therefore thus saith the Lord; Behold, I will punish Shemaiah the Nehelamite, and his seed: he shall not have a man to dwell among this people; neither shall he behold the good that I will do for my people, saith the Lord; because he hath taught rebellion against the Lord.

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.

Thus saith the Lord; Cursed be the man that trusteth in man, and maketh flesh his arm, and whose heart departeth from the Lord.

For he shall be like the heath in the desert, and shall not see when good cometh; but shall inhabit the parched places in the wilderness, in a salt land and not inhabited.