This Bible contradiction is from the Skeptic's Annotated Bible.
John 12:40 View context
He hath blinded their eyes, and hardened their heart; that they should not see with [their] eyes, nor understand with [their] heart, and be converted, and I should heal them.
2 Thessalonians 2:11-12 View context
And for this cause God shall send them strong delusion, that they should believe a lie:
That they all might be damned who believed not the truth, but had pleasure in unrighteousness.
2 Corinthians 4:3-4 View context
But if our gospel be hid, it is hid to them that are lost:
In whom the god of this world hath blinded the minds of them which believe not, lest the light of the glorious gospel of Christ, who is the image of God, should shine unto them.