Didn't know it was the only one...but I know the Domincan Republic has a Bible on its flag.
On government and military flags there is the state?s coat of arms in the middle of the cross.
Zeljko Heimer, 12 Dec 1995
The government of the Dominican Republic adds the national coat of arms in the center of the cross. This emblem is similar to the flag design and shows a bible, a cross of gold, 4 Dominican flags and two spears on a pattern from the flag. there are bracches of olive and palm around the shield and above on a ribbon is the motto "Dios, Patria, Libertad" meaning "God, Fatherland, Liberty." The blue is said to stand for Liberty, red for the fire and blood of the independence struggle and the white cross is a symbol of sacrifice. Below the shield is another ribbon bearing the name of the country "Rep?blica Dominicana".
Dave Martucci, 12 Oct 1999