Teddy Roosevelt commissioned Augustus St. Gaudens to re-design the $20 gold piece in 1906. Roosevelt and St. Gaudens believed it was sacrilegious to use the word "God" on money because it could be used for gambling, or other immoral transactions.
The 1907, and early 1908 St. Gaudens double eagles are called "no motto." In God We Trust was added to the $20 gold coins later in 1908 due to public outcry.