After seeing the confused and incorrect statement that “atheism isn’t supported by evidence” for the umpteenth time, I thought I’d simply write a fairly lengthy response in hopes of allowing me to either copy/paste or merely post a link the next gazillion times I see it posted somewhere…
When one makes a claim, they have to offer a reason for someone to accept it. This is known as a warrant. Different people may accept different warrants for different reasons. For instance, someone may accept the claim that the person emailing them is really a Nigerian prince in a bit of a financial bind because their eagerness to get rich quick overrides their skepticism. Likewise, some people will consider a candidate’s campaign promises as a warrant for electing them without first checking their record.
When it comes to the issue of gods, the believer is the claimant. They are claiming that their god(s) exist. Someone else then asks for a warrant to accept this claim. Most seem willing to accept warrants for god claims that for anything else would be unacceptable (ie – emotional appeals, faith, etc), while others hold such claims to the same standard that they’d hold claims by alleged Nigerian princes and even claims that it’s safe to cross the street. That standard is requiring evidence as a necessary warrant. Those who do this have no choice but to not accept such claims since there is no evidence for any gods, and are then called atheists.
Now to be clear, there are some atheists who assert that there are no gods, but that is a claim without hard evidence, but still arguably supported in part by the lack of evidence to support the existence of a god. There are also atheists who assert there are no gods purely on faith or as a dogmatic tenet of some faith based religion (ie – sects of Buddhism, Scientology, Raellians, etc). However, the vast majority of atheists I’ve ever heard of or encountered are the type of atheists I described earlier who, due to esteeming logic and evidence, don’t accept any god claims for they all lack necessary warrants.
So what all this means is that your statement, “atheism isn’t supported by evidence” is a nonsensical statement for it’s not the atheist making a claim, it’s the theist. The atheist has no burden of proof since he or she is not making a claim, but rather examining a theist’s claim and finding it lacking a sufficient warrant for acceptance.