The ability to know God is not something that is natural to man. We lost that ability in the fall and by our own work we will NEVER get it back. We are helpless to know what we do not know, helpless to see what is hidden from our eyes and helpless to change the manner in which we both see the world and even more helpless to change what we love and what we hate. That hatred is driven by the state of our hearts. Jesus told Nicodemus: "And this is the condemnation, that the light has come into the world, and men loved darkness rather than light, because their deeds were evil." (John 3:19, NKJV) But God promises here in Hebrews that for everyone who is inside the Kingdom, everyone who has had their hearts transformed, that these will absolutely be made over and given both the desire and the ability to KNOW HIM!