I will surely

Numbers 23:19
God is not a man, that He should lie, or a son of man, that He should change His mind. Does He speak and not act? Does He promise and not fulfill?

this evil

Numbers 14:27-29
"How long will this wicked congregation grumble against Me? I have heard the complaints that the Israelites are making against Me. . . .

Numbers 26:65
For the LORD had told them that they would surely die in the wilderness. Not one was left except Caleb son of Jephunneh and Joshua son of Nun.

1 Corinthians 10:5, 11
Nevertheless, God was not pleased with most of them, for they were struck down in the wilderness. . . .

Hebrews 3:19
So we see that it was because of their unbelief that they were unable to enter.