Even in the midst of the Christmas season, churches in the US are failing to draw a substantial crowd.

Gallup today released a poll confirming that less than half of Americans (39%) have visited a church, synagogue, mosque, temple or other religious observance service in the last seven days.

This was despite 56% of Americans saying in the same poll that religion was "very important" to their everyday lives.

"This measure of church attendance is based on individuals' assessments of their own behaviour and is not always directly related to actual attendance on a weekly basis," Gallup noted.

"Various studies over the years have suggested that Americans may over-report their attendance at religious services when compared with other objective measures of their actual attendance."

The statistics are in line with the general trends that have existed since recording of these numbers began.

Between 1964 and 2013, the numbers who reported to have attended a religious service in the last seven days has fluctuated between approximately 35% and 45%, with the lowest in 2011 (37%) and the highest in 2000, 2002 and 2004 (all 44%).

A substantial spike emerged in the mid-1950s and early 1960s where this rose to between 45% and 50%.

The same story is seen in data covering those who identify religion as being very important in their daily life. Although data on this is less available, there is a spike in the early 1950s - 1952 saw 75% of respondents describing religion as very important to their daily life.

Since 1976, the numbers of people describing religion as very important to their daily life ranges from 50% to 65%.

This may be a reflection of people being spiritual more than actively religious.

Thom Rainer, the CEO of Lifeway Christian resources, has suggested that many churches are too casual about their membership, and are not engaged enough with each other as a community.

"Members are less likely to be absent if they know someone misses them," he wrote out on the website in August.

He argued that churches should require an entry class for membership because "by doing so, the church makes a statement that membership is meaningful".