'Unbelief' in the Bible

And He did not do many miracles there because of their unbelief.

And He was amazed at their unbelief.Now He was going around the villages in a circuit, teaching.

Immediately the father of the boy cried out, “I do believe! Help my unbelief.”

Later, He appeared to the Eleven themselves as they were reclining at the table. He rebuked their unbelief and hardness of heart, because they did not believe those who saw Him after He had been resurrected.

What then? If some did not believe, will their unbelief cancel God’s faithfulness?

He did not waver in unbelief at God’s promise but was strengthened in his faith and gave glory to God,

True enough; they were broken off by unbelief, but you stand by faith. Do not be arrogant, but be afraid.

And even they, if they do not remain in unbelief, will be grafted in, because God has the power to graft them in again.

one who was formerly a blasphemer, a persecutor, and an arrogant man. But I received mercy because I acted out of ignorance in unbelief.

So we see that they were unable to enter because of unbelief.