“That is because they believe, then disbelieve, so a seal is set upon their hearts so that they do not understand.”
quran
“They swear by Allah that they did not speak, and certainly they did speak, the word of unbelief, and disbelieved after their Islam, and they had determined upon what they have not been able to effect, and they did not find fault except because Allah and His Apostle enriched them out of His grace; therefore if they repent, it will be good for them; and if they turn back, Allah will chastise them with a painful chastisement in this world and the hereafter, and they shall not have in the land any guardian or a helper.”
“And when those who disbelieve see you, they do not take you but for one to be scoffed at: Is this he who speaks of your gods? And they are deniers at the mention of the Beneficent God.”
“Those who disbelieved from among the followers of the Book and the polytheists could not have separated (from the faithful) until there had come to them the clear evidence: / An apostle from Allah, reciting pure pages, / Wherein are all the right ordinances.”
“This We requited them with because they disbelieved; and We do not punish any but the ungrateful.”
“Then did I punish those who disbelieved, so how was the manifestation of My disapproval? / Do you not see that Allah sends down water from the cloud, then We bring forth therewith fruits of various colors; and in the mountains are streaks, white and red, of various hues and (others) intensely black? / And of men and beasts and cattle are various species of it likewise; those of His servants only who are possessed of knowledge fear Allah; surely Allah is Mighty, Forgiving.”
“We are, I know not how, double in ourselves, so that what we believe we disbelieve, and cannot rid ourselves of what we condemn”
Michel de Montaigne