Hebrews 4:1-2 ESV
" Therefore, while the promise of entering his rest still stands, let us fear lest any of you should seem to have failed to reach it. For good news came to us just as to them, but the message they heard did not benefit them, because they were not united by faith with those who listened."
Some are unable to hear the good news. Their hearts reject it outright, saying there is no God, or if there is, he does not have son. Like stones of a path on which the seed of truth is unable to find any soil for taking root, the word bounces off the hardness of their forehead.
Some hear the good news but fail to live in obedience to that word. They listened with ears and mind, but not with their hearts. They may speak with knowledge of God without knowing Him or being known by Him. The espoused faith is not expressed in their lives.
It is by faith we find salvation. It is with faith that one truly hears and receives the grace of God.