Numbers 14:35
I, the LORD, have spoken. Surely this will I do to all this wicked congregation who are gathered together against me: in this wilderness they shall come to a full end, and there they shall die."
Numbers 23:19
God is not man, that he should lie, or a son of man, that he should change his mind. Has he said, and will he not do it? Or has he spoken, and will he not fulfill it?
Numbers 14:27-29
"How long shall this wicked congregation grumble against me? I have heard the grumblings of the people of Israel, which they grumble against me.
Numbers 26:65
For the LORD had said of them, "They shall die in the wilderness." Not one of them was left, except Caleb the son of Jephunneh and Joshua the son of Nun.
1 Corinthians 10:5
Nevertheless, with most of them God was not pleased, for they were overthrown in the wilderness.
1 Corinthians 10:11
Now these things happened to them as an example, but they were written down for our instruction, on whom the end of the ages has come.
Hebrews 3:19
So we see that they were unable to enter because of unbelief.