Most students think that writing means writing down ideas, insights, visions. They feel that they must first have something to say before they can put it down on paper. For them writing is little more than recording a pre-existent thought.
But with this approach true writing is impossible. Writing is a process in which we discover what lives in us. The writing itself reveals what is alive.....The deepest satisfaction of writing is precisely that it opens up new spaces within us of which we were not aware before we started to write. To write is to embark on a journey whose final destination we do not know.
Henri Nouwen in Reflections on Theological Education.
Quoted on page 285 of Philip Yancey's Soul Survivor, without any page/chapter reference.