Acts 28:24-28 (ESV)
And some were convinced by what he said, but others disbelieved. And disagreeing among themselves, they departed after Paul had made one statement: “The Holy Spirit was right in saying to your fathers through Isaiah the prophet:
“‘Go to this people, and say,
“You will indeed hear but never understand,
and you will indeed see but never perceive.”
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.’
Therefore let it be known to you that this salvation of God has been sent to the Gentiles; they will listen.”
Some heard and responded in faith to Paul’s presentation of the Gospel and some did not. That might be the results of every preacher, teacher, speaker and/or teller of truth could say every time they finished speaking. This is a hard truth. This is even harder when you consider the content of the message Paul is telling them in the above passage. We can tell people stories in an entertaining way and they typically believe them. The news can paint an actually event with the political twist they want and people will believe it. We can make up and fabricate a complete lie, tell it with convincing passion and people will believe it. Yet, Paul speaks the truth about the resurrection of Jesus Christ and some of these Jewish hearers do not respond in faith. Why? Because God, the the prophets, prophesied that they would not. Some would and some wouldn’t. Remember this is a spiritual battle. Note what Paul will later write about this very aspect of not responding:
2 Corinthians 4:3-4 (ESV)
And even if our gospel is veiled, it is veiled to those who are perishing. In their case the god of this world has blinded the minds of the unbelievers, to keep them from seeing the light of the gospel of the glory of Christ, who is the image of God.
Satan does not want people to see the glory of the gospel. The combination of man’s hard hearts and Satan’s blinding their eyes equates to what we read above. God wants to reveal Himself to us, but man and Satan want to close our eyes to see Him.