The following quotes are by Sinclair Ferguson. They are taken from his book A Heart For God. Ferguson writes clearly about the importance of knowing God.
What is the most important thing in the world to every Christian? It is to grow in the knowledge of God (p. 1).
When people truly know God and are growing in a genuine relationship with him, however, their lives are marked by integrity and reality. They do not treat dishonesty of the heart or of the lips indifferently. They are, in a word, holy. But our age is frightened of holiness. It is all the more tragic, therefore, that the church has also become frightened of holiness. It likes nothing less than to be different. The same may be true of us individually. Why? Because we do not know God as we should. If we really knew him, it would show in the character of our lives (p. 2).
Knowing God is your single greatest privilege as a Christian, and the one that sensitizes you to every other issue of importance. But is this the issue that lies at the centre of your thinking (p. 4)?