Jesus was never much one for mincing words.
“You have never heard God,” Jesus told the Jews in 5.38, “and you have never seen God,
and His word is not living inside of you.”
It's like he was saying, “The proof in the pudding is the fact that you have not believed the one God has sent.”
He continues in the very next verse with the paradox:
“You search the scriptures…”
They search the Word, but they have not let the Word take residence inside of them.
That says it all.
How about us?