I think this is a question we should often ask ourselves.
Because if we only know of him, then we have a seriously problem.
If we claim the name of God, but we only know of him.
Something isn't lining up. We need to know him, if we are to claim him.
If people know that we claim the name of the Lord, but they don't see Him in our lives, then there is something wrong. People should see God in us if we claim His name. And you need to KNOW Him, if people are to see Him in your life.
I hope this encourages you To KNOW God.
Instead of knowing of him.