WASHINGTON, D.C. -- As many Americans prepare to celebrate Christmas, 72% say religion is important in their lives, including 51% who say it is very important. Christians' attachment to religion is even higher, as 62% find it very important.

Although these findings, from a Dec. 3-12 Gallup poll, show that religion is still very important to a slim majority, they provide further evidence of the long-term decline in the importance of religion in Americans' lives. This decline has also been seen in Gallup's data on waning church attendance and self-identification with a particular religion.

When Gallup first asked Americans to rate the importance of religion in their lives in 1952, 75% said it was very important and 20% fairly important. Those percentages were roughly the same when the question was next asked, in 1965, but by 1978, they had dropped to 52% very important and 32% fairly important. Since then, the percentage identifying religion as very important has fluctuated, rising above 61% in only two single readings: 64% in 2001 after the 9/11 terrorist attacks and 65% one year later. The historical low single reading of 49% was recorded in May 2015.

Over time, Americans have generally been more likely to say religion as a whole is losing, rather than increasing, its influence on American life. With the exception of three readings -- 69% in 1957; and 71% in December 2001 and 53% in March 2002 in the wake of the 9/11 terrorist attacks -- no more than half of the public has viewed religion as gaining influence.