I would have to agree somewhat with this. Faith isn't something just for the "theists", like we have to have faith in our speech, in what we are doing as justified and everything else we do in daily life. It simply requires faith.
But I look at the question of belief like this, if someone asks you if you believe in God, the answer is not implying a factual device. Rather, its clearly explicating what you believe, since thats all thats being asked for. Anything else is a personal implication, and is something that should be discussed among people who share similar views.
But when it comes down to the main question and the point the OP is making, a belief that one holds with certainty is still a belief, regardless of whether or not it involves the opinion (as oppositional they tend to be) of others.
If you believe that atheism is simply a lack of belief in the existence of God, then its a belief. If your an atheist that claims to belief that there is no God while continuing to advocate that you believe atheism is simply a lack of belief in the existence of God then its a belief. Every single idea and device used to express and uphold our own mental sanity and consciousness is based upon what we believe. Even if these believes latter turn into facts and literal self help equations, they are still beliefs.