Matthew 12:34
You children of snakes! Since you are evil, how do you expect to speak good things? For the mouth speaks what the heart is filled with.
Matthew 13:14-15
So, the prophecy of Isaiah is being fulfilled by them, which says, [Isa. 6:9f] 'You will hear all right, but you will not understand [what you hear]. You will see all right but you will not perceive [what you see].
John 5:44
How can you believe [in me] when you [offer and] accept honors from one another, but do not try to obtain the honor that comes from the only God?
John 8:43
Why do you people not understand what I am saying? It is because you cannot [bear to] listen to my message.
John 12:39-40
They were not able to believe because Isaiah also said [Isa. 6:10],
Acts 14:16
God allowed all nations to go their own way in past generations,
Romans 1:21-23
Now they knew who God was, but they did not honor Him as God or thank Him [for their blessings]. Instead they engaged in their useless speculations and their foolish minds were filled with [spiritual] darkness.
Romans 1:28
And since these people refused to acknowledge God, He has allowed [or, abandoned] them to have degraded minds and to practice those things which they should not do.
Romans 11:8-10
as it has been written [Isa. 19:10], "God gave them a spirit of numbness [i.e., they developed a spiritual insensitivity to God and His word]. [He gave them] eyes to see with [but they would not look], and ears to hear with [but they did not listen]. And they still have this spirit."
2 Corinthians 4:3-4
For even if our Gospel message is veiled, it is veiled [only] from those who are lost.
2 Thessalonians 2:9-12
The coming [of this lawless person] is according to the work of Satan, [and will be] attended by all kinds of powerful [i.e., miraculous] signs and false wonders,
2 Peter 2:14
Their eyes are filled with sexual lust, and they are never satisfied when it comes to sinning. They entice unstable people and have hearts trained to be greedy [i.e., they continually desire the possessions of others]. [In this condition] they are under God's curse.