Authors:

If a man serves not God only, then surely he serves the devil.

Martin Luther, Henry Bell (Captain.), Joseph KERBY, Anton Lauterbach (1818). “The Familiar Discourses of Dr. Martin Luther ... Translated ... by Captain Henry Bell ... A New Edition, Revised ... by J. Kerby, Etc”, p.60
If a man serves not God only, then surely he serves the devil.