I think the intellectually honest approach is to just admit we cannot know for sure whether there is a God with a purpose for us. Hence, agnosticism.
This seems fair. Any time I've tried to say that there's no god based on the idea that he's not doing anything, it's met with arguments like:
1) How do YOU know he's not doing anything? Maybe he's maneuvering things to bring about salvation on his own time table, and not yours.
2) Why should god do anything? Who are you to say what an almighty god would decide is the right thing to do?
Those are unarguable arguments, since I don't have any almighty gods lying around that I can talk to about it. (None that talk back at least!)
In the end I haven't seen any evidence for a god, where the definition of "god" has any meaning. On the other hand, I see abundant evidence that such a god doesn't exist. The most striking of this is the many missed opportunities to prevent disasters.
A god that sits by and watches sentient creatures slaughtered by forces he could easily stop either doesn't exist, or isn't a god I'd want to know anyway.
So for me, no god. And thus atheism. But it's only enough of an argument to convince me, not something I'd use on someone else.
Dave