because.

John 8:19, 55
"Where is Your Father?" they asked Him. "You do not know Me or My Father, " Jesus answered. "If you knew Me, you would know My Father as well." . . .

John 15:21, 23
But they will treat you like this on account of My name, because they do not know the One who sent Me. . . .

John 17:3, 25
Now this is eternal life, that they may know You, the only true God, and Jesus Christ, whom You have sent. . . .

Luke 10:22
All things have been entrusted to Me by My Father. No one knows who the Son is except the Father, and no one knows who the Father is except the Son, and those to whom the Son chooses to reveal Him."

1 Corinthians 2:8
None of the rulers of this age understood it. For if they had, they would not have crucified the Lord of glory.

2 Corinthians 4:3-6
And even if our gospel is veiled, it is veiled to those who are perishing. . . .

2 Thessalonians 1:8
in blazing fire. He will inflict vengeance on those who do not know God and do not obey the gospel of our Lord Jesus.

2 Thessalonians 2:10-12
and with every wicked deception directed against those who are perishing, because they refused the love of the truth that would have saved them. . . .

1 Timothy 1:13
I was formerly a blasphemer, a persecutor, and a violent man; yet because I had acted in ignorance and unbelief, I was shown mercy.

1 John 3:1
Behold what manner of love the Father has given to us, that we should be called children of God. And that is what we are! The reason the world does not know us is that it did not know Him.

1 John 4:8
Whoever does not love does not know God, because God is love.

1 John 5:20
And we know that the Son of God has come and has given us understanding, so that we may know Him who is true; and we are in Him who is true--in His Son Jesus Christ. He is the true God and eternal life.