They dont believe because Christ didnt die for them as He did His Sheep Jn 10:26
26 But ye believe not, because ye are not of my sheep, as I said unto you.
Believing in Christ comes with the fact He died for you. So if one never believes, its because He never died for them taking away their sins. See His Death takes away sin and its awful consequences 1 Jn 3:5
And ye know that he was manifested to take away our sins; and in him is no sin. Unbelief is the consequences of sin
26 But ye believe not, because ye are not of my sheep, as I said unto you.
Believing in Christ comes with the fact He died for you. So if one never believes, its because He never died for them taking away their sins. See His Death takes away sin and its awful consequences 1 Jn 3:5
And ye know that he was manifested to take away our sins; and in him is no sin. Unbelief is the consequences of sin
What did Jesus say about the Jews and His PARABLES?
14 Indeed, in their case the prophecy of Isaiah is fulfilled that says:
“‘“You will indeed hear but never understand,
and you will indeed see but never perceive.”
15 For this people's heart has grown dull,
and with their ears they can barely hear,
and their eyes they have closed,
lest they should see with their eyes
and hear with their ears
and understand with their heart
and turn, and I would heal them.’
It fulfills Isaiah
9 And He said: 'Go, and tell this people: hear ye indeed, but understand not; and see ye indeed, but perceive not.
10 Make the heart of this people fat, and make their ears heavy, and shut their eyes; lest they, seeing with their eyes, and hearing with their ears, and understanding with their heart, return, and be healed.'
Paul explains it this way
“God gave them a spirit of stupor,
eyes that would not see
and ears that would not hear,
down to this very day.”
The Jews could not understand because what God did to them.
It had NOTHING to do with Jesus not dying for them because He did!