As people who have moved from a faith position to another or to none at all, we migjt be especially aware of the many shades between belief and non-belief.
Believers themselves experience doubt all the time. Faith and doubt are so closely connected they simply cannot be separated, like two sides of a coin. In some ways doubt is an expression of deep faith. In the sense that the anxiety that surrounds the very concept of "doubt" can only really visit those who take their faith very seriously in the first place.
I have moved beyond having mere doubts. I have become skeptical about human knowledge itself. More than simply having the wrong answers, it is not clear that humans are able to ask the right questions.
A dog can't do calculus and a cat can't budget for his cat food. How do we even know whether we are asking the right questions regarding "God"? If we are the products of a blind evolutionary processes, then what possible suvival function would be provided by being able to ask and offer answers for ultimate questions?
How do we know our mutteeings about God or not-God make any more sense than a wolf howling at the moon?
This is what I mean by calling myself agnostic.