Mark 4:12
This is so that even though they see, they will see and yet not perceive. And even though they hear, they will hear and yet not understand. For if they did, they would turn [back to God] again and receive forgiveness."
Mark 8:17-21
Jesus, being aware of what they were thinking, said, "Why are you reasoning about not having any bread? Have you not yet perceived or understood? Have your hearts become insensitive?
Ephesians 2:11
So, you Gentiles by birth should remember what you once were. You are called "Uncircumcision" by those who are called "Circumcision" [i.e., the Jews], (which refers to a physical procedure performed by people).
2 Thessalonians 2:10-12
and all kinds of wicked deception toward those people who are perishing [spiritually], because they refused to love the truth so they could be saved.