Many Americans are devoted readers of Scripture: More than a third (37%) say they read the Bible or other Holy Scriptures at least once a week, not counting worship services. But Americans as a whole are much less inclined to read other books about religion. Nearly half of Americans who are affiliated with a religion (48%) say they “seldom” or “never” read books (other than Scripture) or visit websites about their own religion, and 70% say they seldom or never read books or visit websites about other religions.
—Pew 2010 U.S. Religious Knowledge Survey