There is no external cure for stupidity, dumbness, foolishness, or whatever term is used to refer to a willing blindness.

The way of a fool is right in his own eyes -Proverbs 12:15a

…their minds became dark and confused. Claiming to be wise, they instead became utter fools. -Romans 1:21b-22

Behind stupidity is a forceful willingness to avoid any truth that would cause one to lose his pride, comfort, position, wealth, or planning. A determination to decide that whatever he wants to be true to be is true.

A time is coming when people will no longer listen to [solid] and wholesome teaching. They will follow their own desires and will look for teachers who will tell them whatever their ears want to hear. -2 Timothy 4:3

Wise advice cannot cure stupidity. Undisputable facts cannot, and harsh experience cannot. Even the fear of death.

You cannot separate fools from their foolishness, even [if you could] grind them like grain with mortar and pestle. -Proverbs 27:22

God gives wisdom, insight, perception, and discernment to the few who are willing to humble themselves and admit they are dependent on Him - those who accept that they should not believe whatever feels right by natural instinct.

There is a way that seems right to a man, but its end is the way to death. -Proverbs 14:12

The fear of the Lord is the beginning [foundation] of knowledge; Fools despise wisdom and instruction. -Proverbs 1:7

Those who trust in The World and its corrupt systems will be deceived.

Then they will be condemned for enjoying evil rather than believing the truth. -2 Thessalonians 2:12

Those who reverence God and seek his blessing will receive wisdom that is beyond what human senses can perceive.

Stop deceiving yourselves. If you think you are wise by this world’s standards, you need to become a fool to be truly wise. -1 Corinthians 3:18

Surely [God,] you desire integrity in the inner self, and you teach me wisdom deep within. -Psalm 51:6