'Unbelief' in the Bible

And he did not many mighty works there because of their unbelief.

And he marvelled because of their unbelief. And he went round about the villages teaching.

Straightway the father of the child cried out, and said, I believe; help thou mine unbelief.

And afterward he was manifested unto the eleven themselves as they sat at meat; and he upbraided them with their unbelief and hardness of heart, because they believed not them that had seen him after he was risen.

yet, looking unto the promise of God, he wavered not through unbelief, but waxed strong through faith, giving glory to God,

Well; by their unbelief they were broken off, and thou standest by thy faith. Be not highminded, but fear:

And they also, if they continue not in their unbelief, shall be grafted in: for God is able to graft them in again.

though I was before a blasphemer, and a persecutor, and injurious: howbeit I obtained mercy, because I did it ignorantly in unbelief;

Take heed, brethren, lest haply there shall be in any one of you an evil heart of unbelief, in falling away from the living God:

And we see that they were not able to enter in because of unbelief.