Ephesians 4:18

darkened in their understanding, alienated from the life of God through the ignorance that is in them, because of the hardness of their heart;

Ephesians 2:12

that you were at that time without Christ, being aliens from the community of Israel, and strangers to the covenants of promise, having no hope, and having no God in the world:

Galatians 4:8

But, then, because you knew not God, you were enslaved to those who, by nature, are not gods:

1 Thessalonians 4:5

not in passionate desire, as the Gentiles do, who know not God;

Acts 17:30

Yet the times of this ignorance God overlooked; but now, he commands all men everywhere to repent:

Romans 1:21-23

because, when they knew God, they did not glorify him as God, nor were they thankful; but they became perverse in their reasonings, and their wicked heart was darkened;

Romans 11:25

For I do not wish you, brethren, to be ignorant of this mystery lest you be wise in your own conceit that blindness has happened to Israel in part, till the full number of the Gen tiles shall have come in.

Matthew 13:15

For the heart of this people has become fat; and with their ears they hear heavily; and their eyes they have closed; lest they should see with their eyes, and hear with their ears, and understand with their heart, and should turn to me, and I should give them health.

Mark 3:5

And looking around on them with anger, being grieved for the hardness of their heart, he said to the man: Stretch forth your hand; and he stretched it forth: and his hand was restored.

John 12:40

He has blinded their eyes, and hardened their heart, lest they should see with their eyes, and understand with their heart, and should turn, and I should give them health.

Acts 26:17-18

delivering you from the people, and from the Gentiles, to whom now I send you,

Romans 1:28

And as they refused to acknowledge God, God delivered them up to an undiscerning mind, to do detestable things;

Romans 2:19

if you are also confident that you yourself are a guide for the blind, a light to those who are in darkness,

Romans 8:7-8

Because the mind of the flesh is enmity against God; for it is not subject to the law of God, nor indeed can it be.

1 Corinthians 1:21

For, since in the wisdom of God, the world, by its wisdom, knew not God, it has pleased God, through the foolishness of what is preached, to save those who believe.

2 Corinthians 3:14

But their minds were blinded: for till this day, in the reading of the old covenant, the same vail remains not taken away, which vail is removed in Christ.

2 Corinthians 4:4

whose unbelieving minds the god of this age has darkened, so that the light of the glorious gospel of Christ, who is the image of God, should not shine to them.

Colossians 1:21

And you, who were formerly alienated and enemies in your mind by wicked works, yet now has he reconciled

James 4:4

Adulterers and adulteresses, know you not that the friend ship of the world is enmity to God? Whoever, therefore, will be a friend of the world, is an enemy of God.

1 John 2:11

He that hates his brother is in darkness, and walks in darkness; and he knows not whither he goes, because darkness has blinded his eyes.

Treasury of Scripture Knowledge

Summary

Having the understanding darkened, being alienated from the life of God through the ignorance that is in them, because of the blindness of their heart:

Bible References

The understanding

Acts 17:30
Yet the times of this ignorance God overlooked; but now, he commands all men everywhere to repent:
Acts 26:17
delivering you from the people, and from the Gentiles, to whom now I send you,
Romans 1:21
because, when they knew God, they did not glorify him as God, nor were they thankful; but they became perverse in their reasonings, and their wicked heart was darkened;
1 Corinthians 1:21
For, since in the wisdom of God, the world, by its wisdom, knew not God, it has pleased God, through the foolishness of what is preached, to save those who believe.
2 Corinthians 4:4
whose unbelieving minds the god of this age has darkened, so that the light of the glorious gospel of Christ, who is the image of God, should not shine to them.
Galatians 4:8
But, then, because you knew not God, you were enslaved to those who, by nature, are not gods:
1 Thessalonians 4:5
not in passionate desire, as the Gentiles do, who know not God;

Alienated

Ephesians 2:12
that you were at that time without Christ, being aliens from the community of Israel, and strangers to the covenants of promise, having no hope, and having no God in the world:
Romans 8:7
Because the mind of the flesh is enmity against God; for it is not subject to the law of God, nor indeed can it be.
Galatians 4:8
But, then, because you knew not God, you were enslaved to those who, by nature, are not gods:
Colossians 1:21
And you, who were formerly alienated and enemies in your mind by wicked works, yet now has he reconciled
1 Thessalonians 4:5
not in passionate desire, as the Gentiles do, who know not God;
James 4:4
Adulterers and adulteresses, know you not that the friend ship of the world is enmity to God? Whoever, therefore, will be a friend of the world, is an enemy of God.

Because

Romans 1:21
because, when they knew God, they did not glorify him as God, nor were they thankful; but they became perverse in their reasonings, and their wicked heart was darkened;
Romans 2:19
if you are also confident that you yourself are a guide for the blind, a light to those who are in darkness,
1 John 2:11
He that hates his brother is in darkness, and walks in darkness; and he knows not whither he goes, because darkness has blinded his eyes.