The survey conducted by Harris Poll found that 42 percent of US adults are not "absolutely certain" there is a God compared to 34 percent who felt that way when asked the same question three years ago.

Among the various religious groups, 76 percent of Protestants, 64 percent of Catholics and 30 percent of Jews said they are "absolutely certain" there is a God while 93 percent of Christians who describe themselves as "Born Again" feel certain God exists.

When questioned on whether God is male or female, 36 percent of respondents said they think God is male, 37 percent said neither male nor female and 10 percent said "both male and female."

Only one percent think of God as a female, according to the poll.

Asked whether God has a human form, 41 percent said they think of God as "a spirit or power than can take on human form but is not inherently human."

As to whether God controls events on Earth, 29 percent believe that to be the case while 44 percent said God "observes but does not control what happens on Earth".

The survey was conducted online between October 4 and 10 among 2,010 US adults.