Stiffneckedness and unbelief

1. 2 Ne. 32: 7
   7 And now I, Nephi, cannot say more; the Spirit stoppeth mine utterance, and I am left to mourn because of the unbelief, and the wickedness, and the ignorance, and the stiffneckedness of men; for they will not search knowledge, nor understand great knowledge, when it is given unto them in plainness, even as plain as word can be.
2. 3 Ne. 15: 18
   18 And now, because of stiffneckedness and unbelief they understood not my word; therefore I was commanded to say no more of the Father concerning this thing unto them.