When I first started the process of coming to terms with the fact that I no longer believed in gods, I remember that it involved some degree of effort. Prior to about age 14, I had believed in gods without question. As it gradually began to dawn on me that there was no evidence to support the existence of gods, I fought against this realization and tried to maintain my religious belief. That is to say, I expended effort toward the goal of not becoming an atheist. Of course, I failed miserably. I no longer believed in gods, and no amount of effort was successful in changing that. Within a couple years, I'd finally be able to admit to myself that I was an atheist.
Since that time, I don't think it has taken any effort to sustain my atheism. There is nothing I have to keep doing in order to remain an atheist. There is nothing that if I were to stop doing it might return me to god belief. In short, I can't think of any way that I've needed to expend effort to remain an atheist. Atheism is something I am; it really isn't anything I have to do.
What a sharp contrast this is with skepticism and freethought, both of which do seem to require sustained effort! Without vigilance and hard work, I could drift out of skepticism. As I have become more practiced at it, it has become somewhat easier for me. The odds of my abandoning it now are much less than they would have been a couple decades ago. Still, it is not something I'd call easy. I do slip out of skepticism from time-to-time. Sustaining skepticism takes effort in a way that sustaining atheism never has.
As for freethought, it is much newer to me than skepticism. I came to it much later in life, and I have not reached the point where it has become second nature. I'm not even sure there is such a point. It takes even more effort, and it is something I could drift out of much easier. It has really been only in the past few years that I have been able to catch myself doing just that on occasion. I think it is fair to say that sustaining freethought requires even more effort for me than sustaining skepticism. In fact, it is something to which I have to make an active commitment.
Atheism, skepticism, and freethought are all aspects of who I am. Since atheism requires no effort to sustain, it often sinks into the background. It is not something I must think about every day. In fact, if it was not for religious believers promoting their faith at every turn and attempting to erode the separation of church and state, atheism is not something I would think about much at all. On the other hand, skepticism and freethought are on my mind more often because they do require some effort on my part.
