You probably just didn't except it. Secular refers to things that are simply not considered sacred in a given context. For example music can be secular or sacred depending on the subject matter. Atheism is a belief that there are no deity's. These things aren't even the same. An atheist who has a cross in their home does make the object secular because he doesn't believe in its symbolism. A theist who sanctified his entire home does not make his shoes sacred.