In Matthew 13, we see Jesus explain why the people of His day did not understand His parables or His purpose.
And in them is fulfilled the prophecy of Esaias, which saith, By hearing ye shall hear, and shall not understand; and seeing ye shall see, and shall not perceive: For this people's heart is waxed gross, and their ears are dull of hearing, and their eyes they have closed; lest at any time they should see with their eyes, and hear with their ears, and should understand with their heart, and should be converted, and I should heal them.
People may not have been actively deciding to ignore Him, but their entire life was set in a manner to prevent proper hearing. This is still true today. How much society trains us to ignore God’s word. We may not engage in an active, conscious effort to ignore God, but our lives may be set in such a way He is hard to hear. This can be with truly disastrous results, as with those who deny God. For those of us who believe, this block to hearing God can still be very problematic.