Romans 1:22
While they professed to be wise, they became fools,
1 Corinthians 8:4
Now as to eating food that has been offered to idols, we know well that an idol has no real existence in the universe, and that there is no God but One.
2 Corinthians 4:4
Among them the god of this age has blinded the understanding of the unbelieving so that the sunshine of the gospel of God, should not dawn upon them.
Ephesians 4:18
having their understanding darkened, alienated from the life of God through the ignorance that is in them, because of the hardening of their hearts.
Ephesians 5:8
For you were once darkness, but are now in the Lord.