To Anders Andersen
You got your definition of atheism wrong and are thus creating a straw man argument. Only by coming up with your own (false) definition of atheism, you can make your argument. However, almost all of the people who call themselves atheist do not claim to know there are no gods, they simply do not believe in any gods. Your argument applies to almost nobody. Redefining the label I apply to myself doesn't suddenly change my (lack of) beliefs into a claim of knowledge.
Stepping from strong atheism to soft atheism; soft espouses “lack of belief” or “absence of belief” which is an illogical position to take if one is making a conscious decision not to belief. Under such a worldview, a newborn, dog or cat qualifies as a soft atheist, for they lack belief in God also.
Nice rookie try.