Ecclesiastes 12:13 Let us hear the conclusion of the whole matter: Fear God and keep his commandments: for this is the whole duty of man.
We prove what we think of God by the way we live our lives. We will live no better than the level at which we honor and reverence Him.
If we see the Lord as being high and holy; if we see Him as being a God of judgment; if we see Him as being One who hates sin; then we will live like we believe that.
But if we have the idea that God winks at sin, that He might not really judge the world; then we will live at a much lower level.
God wants us to live a life that He can use and bless. He wants us to walk in awe of Him. He wants our hearts to be so filed with respect for Him that we would rather die than to dishonor Him and His name. That's the essence of fearing God.