In order to say that you truly know someone, you have to spend time with them.
This goes for all of our relationships, including our relationship with God.
In life, no matter where we go or what we achieve, we can never be fully satisfied without God.
Knowing Him and having a relationship with Him is what completes us.
We all have areas of brokenness or pieces of us that are missing in our lives, and the only place to find those pieces are in His presence.
In his book, Love.