Mark 4:12
that "'They may look and look but not see, and listen and listen but not understand, lest perchance they should return and be pardoned.'"
Mark 8:17-21
He perceived what they were saying, and He said to them, "What is this discussion of yours about having no bread? Do you not yet see and understand? Are your minds so dull of comprehension?
Ephesians 2:11
Therefore, do not forget that formerly you were Gentiles as to your bodily condition. You were called the Uncircumcision by those who style themselves the Circumcised--their circumcision being one which the knife has effected.
2 Thessalonians 2:10-12
and by every kind of wicked deception for those who are on the way to perdition because they did not welcome into their hearts the love of the truth, so that they might be saved.