Writer's block is nothing more nor less than your resistance to those words that would have their way with you if you would but surrender to them.
Instead, you say, "No, not these words. I want others."
Well, there are no other words. There are only heart words.
If you would but open your heart and allow what longs to flow from you easy egress, there would be no block. If you would but make your fear subservient to your courage, there would be no block. For fear and courage can coexist, but not as equals. One must take precedence. Fear leads to inaction. Courage to action.
Step through your fear and into your courage. Write through your fear and into your courage. Allow the voice of your Muse to live through you onto the page.
Do it now. Write. Surrender to the story, whatever it is. Dissolve your resistance. And let those words you have run from have their way with you. Now.
Adapted from The Voice of the Muse: Answering the Call to Write, from the "Myth of Writer's Block" section.