Quran 18:56 — The Cave (Al-Kahf)

We only send the messengers as simply deliverers of good news, as well as warners. Those who disbelieve argue with falsehood to defeat the truth, and they take My proofs and warnings in vain.

[18:55] Nothing prevented the people from believing, when the guidance came to them, and from seeking the forgiveness of their Lord, except that they demanded to see the same (kind of miracles) as the previous generations, or challenged to see the retribution beforehand.

[18:57] Who are more evil than those who are reminded of their Lord's proofs, then disregard them, without realizing what they are doing. Consequently, we place shields on their hearts to prevent them from understanding it (the Quran), and deafness in their ears. Thus, no matter what you do to guide them, they can never ever be guided.