Luke 24:25
Then Jesus told them, "O, how foolish you are! How slow you are to believe everything the prophets said!
Mark 7:18
He asked them, "Are you so ignorant? Don't you know that nothing that goes into a person from the outside can make him unclean?
Mark 8:17-18
Knowing this, Jesus asked them, "Why are you discussing the fact that you don't have any bread? Don't you understand or perceive yet? Are your hearts hardened?
Mark 9:19
Jesus told them, "You unbelieving generation! How long must I be with you? How long must I put up with you? Bring him to me!"
Mark 16:14
Finally he appeared to his eleven disciples while they were eating. He rebuked them for their unbelief and stubbornness, because they had not believed those who had seen him after he had risen.
Hebrews 5:11-12
We have much to say about this, but it is difficult to explain because you have become too lazy to understand.