I notice many atheist who try to prove that God does not exist fall into the pit of one the pernicious of logical fallacies to ever exist. Yes my friends I am talking about the dastardly fallacy of the non-sequitur, which is Latin for "huh?".
http://en.wikipedia.org/wiki/Non_sequitur_(logic)
Take this old chestnut for example: The Problem of Evil
Some atheist like argue that just because evil exist this world, that must mean that God does not exist, we see it over and over again these forum. In fact postings or threads related The Problem of Evil are made at 20 per hour. I was bored one day so I counted. I still can't for the life see how The Problem of Evil is an argument against the existence of God? It just does not follow!
Here is another argument made popularized by Professor DeGrasse-Tyson, that is that God cannot exist because of the haphazard way we are put together. That is another non-sequitur.
Basically what atheist have a habit of doing is attack the tenets of religion and then suggest that by attacking the tenets they therefore have made a solid argument against the existence of God. But such is not the case. What they are doing is making an argument against what people think God is and not against the existence of God.