People get a little jumpy sometimes when I mention "activism" in the context of the secular movement. It often brings to mind "evangelical atheists" and concerted efforts to undermine religion. That's a scary picture when we've made so much progress toward establishing inviting communities, engaging in productive dialogues with religious organizations, and improving the atheist image. But I think this comes from a misunderstanding about what a secular group is and could be.
There's a lot of uncertainty surrounding our relationship with religious people and organizations. Many individual members have at least an intuition that there's something genuinely harmful about religion (or particular kinds of religion), and that the world would be better off without it. I strongly sympathize. Many central features of most of the largest religions are frightening and dangerous. On the other hand, even if a secular group wanted to fight religion explicitly, the project would probably fail. It isn't a practical strategy. (I'll happily defend that for anyone who asks me to, but since my goal is to describe an alternative method that would sidestep this issue, I'm not going to use this space to re-hash that apparently endless "confrontation vs. accommodation" debate.)
So a lot of groups make the primary focus community building; one thing atheists lack is a ready-made community center where they know they'll be welcomed and accepted. It's very important secular groups maintain that particular function, whatever else we do in addition. At the very least, a strong community is simply a prerequisite for a successful community-based activist project.
The mistake we frequently make is in thinking that we must either be anti-religious or avoid activism entirely. This is silly. There is a positive approach to activism that makes sense for us, and not only would taking it give us direction, but we're uniquely situated to make rapid and far-reaching improvements to the world should we unite toward this goal.
Religion is not the problem.
"Activism" is about passionate, coordinated efforts to change the world. What secular activism should be depends on what changes we want to make to the world. What are those changes? What counts as "winning" for the secular movement? I don't think "equal social status and protection under the laws for non-religious people" is the answer to that particular question, even if it's definitely a significant improvement to the current situation. (It is, of course, a mission particular organizations within the secular movement should be focusing on. I'm speaking more generally, and especially to student groups.) It's certainly a crucial step along the path, but our preoccupation with science, for example, is evidence that we already have our sights set higher than that.
If we really stop to think about it, I doubt "the end of religion" is the answer either. Imagine that, overnight, all organized religion disappears. Everything else remains the same, but nobody goes to church, nobody prays, and nobody believes in God. I'll definitely grant that this is a net improvement. Shall we call it a day and keep to ourselves from here on out, or is there more work to be done?
Before the advent of this anti-religious miracle, what bothered me about religion was a very simple matter: Many religious memes are powerful deterrents to rational decision making. They can act as parasites that latch onto our cognitive biases and drain away whatever potential we have to inoculate ourselves against them. My concern is not, at heart, with religion itself, but with its exacerbation of irrationality that comes pre-installed in human brains to start with. Self-reinforcing systematic irrationality causes incredible damage, and is plausibly responsible for all of the harm religion has ever done.
If it weren't for this particular feature, I wouldn't care much about religion, and I suspect most atheists (and anti-theists) wouldn't either. Religious people would simply be wrong, like someone who thinks the moon is made of cheese, and that would be that.
This is why we secularists also spend our time educating people about homeopathy, chiropractic, and astrology when we get together in groups. We care about a deeper problem than religion.
We don't so much want the end of religion as the dawn of rationality.
Rationality activism means raising the sanity waterline. The notion of rationality I have in mind amounts to "systematic optimization from inside a human brain". I do not mean, for example, never relying on intuition to make decisions, ignoring emotion, or valuing only quantifiable things. I'm talking about the notion of rationality arising from cognitive science, not Hollywood. Rationality is the art of making decisions that are ever more effective at moving your life and the world toward your values. Note that if moving the world toward your values requires actually interacting with the world, it usually helps to have accurate beliefs about the world. When your map doesn't match the territory, it's a lot harder to get where you're trying to go.