From Thomas Merton's book, New Seeds of Contemplation:
If you write for God you will reach many men and bring them joy.
If you write for men--you may make some money and you may give someone a little joy and you may make a noise in the world, for a little while.
If you write only for yourself you can read what you yourself have written and after ten minutes you will be so disgusted you will wish that you were dead.
If a writer writes so cautiously that he never writes anything that cannot be criticized, he will never write anything that can be read. If you want to help other people you have got to make up your mind to write things that some men will condemn.
This last quote was good for me to read. I opened the book randomly, and that quote jumped out at me. I'm pretty sure the book I plan to write is something some men will condemn, so I guess that's a good thing.