All atheism is not holding beliefs about the existence of 'Gods' - and that is just about it really. It requires no effort beyond thinking.
So I don't think it compares to theism at all: theism has it's various branches and the plethora of rituals and routines, dogma, tribalism, holy books, special songs and words, priestly classes and copious traditions. It seems to me that, for some at least, theism involves activities and effort - which for some may feel intrinsically worthwhile and reinforces their faith.
Dear Gordon,
Okay, fair enough, I am very happy in my findings, and now that I have free space to think about other wonderful things, I will be very British and mention the weather, terrific weather we are having considering it is still officially spring time

and could I also mention well done the Spurs, knowing Spurs fans they will be celebrating this for a very long time, very long time

Oh and just as a aside, you mention activities and effort, yes very true, in Christianity, practice, practice, practice, and yes it does as you put it, reinforce their faith, but I don't think this is just a Christian thing.
Gonnagle.