John 12:39

Therefore could they not believe, because that Isaiah saith again,

John 5:44

How can ye believe, which receive honour one of another, and seek not the honour that cometh of God only?

Isaiah 6:9-10

And so he said, "Go, and tell this people: 'Ye shall hear indeed, but ye shall not understand; ye shall plainly see, and not perceive.

Isaiah 44:18-20

Yet men neither consider nor understand; because their eyes are stopped that they cannot see, and their hearts, that they can not perceive.

John 6:44

No man can come to me except the father, which hath sent me, draw him. And I will raise him up at the last day.

John 10:38

But if I do: though ye believe not me, yet believe the works, that ye may know and believe that the father is in me, and I in him."

2 Peter 2:14

having eyes full of adultery, and that cannot cease to sin, beguiling unstable souls. Hearts they have exercised with covetousness. They are cursed children,

Treasury of Scripture Knowledge

Summary

Therefore they could not believe, because that Esaias said again,

Bible References

They

John 5:44
How can ye believe, which receive honour one of another, and seek not the honour that cometh of God only?
John 6:44
No man can come to me except the father, which hath sent me, draw him. And I will raise him up at the last day.
John 10:38
But if I do: though ye believe not me, yet believe the works, that ye may know and believe that the father is in me, and I in him."
Isaiah 44:18
Yet men neither consider nor understand; because their eyes are stopped that they cannot see, and their hearts, that they can not perceive.
2 Peter 2:14
having eyes full of adultery, and that cannot cease to sin, beguiling unstable souls. Hearts they have exercised with covetousness. They are cursed children,

General references

Exodus 10:20
But the LORD hardened Pharaoh's heart, so that he would not let the children of Israel go.
Deuteronomy 29:4
And yet the LORD hath not given you a heart to perceive, nor eyes to see, nor ears to hear unto this day.
John 1:5
And the light shineth in the darkness, but the darkness comprehended it not.
John 9:18
But the Jews did not believe of the fellow, how that he was blind, and received his sight: until they had called the father and mother of him that had received his sight.
John 10:37
If I do not the works of my father, believe me not.