Quote from A Course in Miracles Text Chapter 18 - THE PASSING OF THE DREAM.

T-18.III.2. As the light comes nearer you will rush to darkness, shrinking from the truth, sometimes retreating to the lesser forms of fear, and sometimes to stark terror. 2 But you will advance, because your goal is the advance from fear to truth. 3 The goal you accepted is the goal of knowledge, for which you signified your willingness. 4 Fear seems to live in darkness, and when you are afraid you have stepped back. 5 Let us then join quickly in an instant of light, and it will be enough to remind you that your goal is light.