Fear -of-the-Lord is the stock biblical term for this either sudden or cultivated awareness that the presence or revelation of God introduces into our lives. We are not the center of our existence. We are not the sum total of what matters. We don't know what's going to happen next.
Fear-of-the-Lord keeps us on our toes with our eyes open. Something is going on around here, and we don't want to miss it. Fear-of-the-Lord prevents us from thinking that we know it all. And it therefore prevents us from closing off our minds or our perceptions from what is new. Fear-of-the-Lord prevents us from acting presumptously and therefore destroying or violating some aspect of beauty, truth, or goodness that we don't recognize or don't understand.
Fear-of-the-Lord is fear with the scary element deleted. So it is often accompanied with the reassurance: "Fear not." But the "fear not" does not result in the absence of fear but rather the transformation into the fear-of-the-Lord. We still don't know what's going on. We're still not in control. We're still deep, deep in mystery.(all emphasis was added by me)
Living the Resurrection (The Risen Christ in Everyday Life) - Eugene H. Peterson (pages 28 and 29).