Mark 4:12
'They may look and look and yet not see, And listen and listen and yet not understand, Lest, perchance, they should turn and be forgiven.'"
Mark 8:17-21
And as He noticed it He said to them, "Why are you discussing the fact that you have no bread? Do you not yet know nor understand? Are your minds so dull?
Ephesians 2:11
So remember that you were once heathen in a physical sense, called the uncircumcised by those who call themselves the circumcised -- though only in a physical sense, by human hands.
2 Thessalonians 2:10-12
and with a completely wicked deception for men who are on the way to destruction, because they refused to love the truth so as to be saved.