I am only an agnostic with respect to the question of creation, because I do not believe that the big bang theory entirely sufficies as an explaination for the beginning of the universe. However, on the question of the existance of god, there is clearly no evidence. The concept of dieties is entirely illogical and contradicts every known fact about physics and the property of matter.
In retrospect, agnosticism is an ambiguous position. An agnostic is like an atheist that lacks the courage of their convictions (and a centrist is like a totalitarian that lacks the courage of their convictions). Someone who is afraid of reaching a conclusion. An agnostic is someone who tries to claim that there can be no truth-statements with respect to the existance of a diety. However, there can be truth statements about it when all physical and logical evidence contradicts the claim that dieties exist.
That being said, I do reject the "radical atheist" viewpoint that anyone who is religious is inherently stupid. Ignorant perhaps, but not stupid. People who are religious are not that way because of they have lesser intelligence than people who do not. They are religious because (1) they were socially conditioned into being religious by their parents and the general culture and (2) they purposefully choose to ignore the evidence to the contrary before their own eyes.
The main flaw with agnosticism is that it easily becomes a form of radical subjectivism. Radical subjectivism as a philosophy can be very irrational because it refuses to aknowledge the extent to which reality exists independantly of what people think. While it is true that there is a degree of subjectivity with respect to what people think, objective reality still exists regaurdless - it does not bend to people's wills.
The entire principle of science is that people's ideas must change and conform in the face of evidence that contradicts those ideas. Radical subjectivism, however, defies the scientific method by implying that reality does conform to people's subjective wills. Objective reality does not function this way. If someone thinks that apples fall upwards, the laws of physics do not reverse as to make the apple fall upwards. Apples still fall downwards. Objective reality still exists, contrary to such irrational beliefs.
Why do people hold irrational beliefs? Not because they are incapable of seeing the truth. Most people are perfectly capable of seeing what is wrong with such beliefs. People hold irrational beliefs because, while they are perfectly aware of the implications of the truth, they fear the implications of the truth. People fear the consequences of the truth, especially in terms of the limits on human capability and life. As a consequence, they hold onto irrational ideas as a protective mechanism. They choose ignorance.
People should not be afraid to point out irrational ideas for what they are. Agnostics are too afraid to declare that the emperor (or diety) has no clothes. This is because the agnostic is not entirely sure wether or not the diety does have clothes. They may very well know that it does not, but their set up a methodology in which they refuse to aknowledge that they do know. While the agnostic proudly proclaims, "I do not know", they most likely actually do know and are in denial, or too afraid to offend the senses of either themselves or others.
The only way to get people to move away from mysticism and towards rationality is to make them, through peaceful arguementation (NOT violence), to reconcile the contradictions between their ideas and objective reality. Their ideas must give way to objective reality or they are choosing to be ignorant. The route of blind, indiscriminate tolerance of all irrational ideas cannot decrease the net amount of irrationality. To the contrary, it only encourages it. This is not to say that people who hold irrational ideas should be persecuted in any way. It does mean, however, that we should not be afraid to employ powerful arguementation to refute their irrationalities.