These maps show the percentage of adults in each state who said they attended church each week (or almost each week) in 2009: 

Click the image below for an interactive version, which categorizes states in quintiles by rank (1-10, 11-20, etc., so the colors don’t match perfectly to the above map): 

Source: Gallop, 2009. The margin of sampling error for most states is ±1 to ±2 percentage points, but is as high as ±4 points for smaller states such as Wyoming, North Dakota, South Dakota, Delaware, and Hawaii.

Map: Shapefiles | Data: Google Fusion Tables