An agnostic is somebody who doesn't know for sure whether there really is a God. That is some people all of the time and all people some of the time.
There are some agnostics who don't know simply because they've never taken pains to try to find out-like the bear who didn't know what was on the other side of the mountain.
There are other agnostics who have taken many pains. They have climbed over the mountain, and what do you think they saw? Only the other side of the mountain. At least that was all they could be sure of. That faint glimmer on the far horizon could have been just Disneyland.