The Pew Forum on Religion and Public Life has been parsing its U.S. Religious Landscape Survey. They found that more than 2/3rds of Americans absolutely believe in God or a universal spirit. Women believe more than men, 77% to 65%. 2/3rds of this group of believers, or about 1/2 of all Americans, absolutely believe in a personal God. The female/male breakdown here crosses the 50% threshold. Of all American women, 58% report an absolutely certain belief in a personal God. Of American men, only 45% agree.
Pew report that women have stronger religious faith and practice across the board, not just on this item. In general, though, women prefer personal relationships to abstract concepts. This, I think, is the heart of the dispute between Carol Gilligan and Lawrence Kohlberg about whether loyalty to people or loyalty to abstract concepts represents the highest level of morality.
I do not read the Pew data as showing that most men are not really religious. I read it as showing that men and women differ somewhat in how they conceive of God and therefore of what they have religious faith in.