@ lightbulb.
Like with the followers of religion, those who self-identify as atheists come in different flavours. The majority, as far as I understand it, do not actually have a belief that htere is no god = rather, their atheism stems from a lack of belief in a god, because, despite the thousands of years of god worship, of all flavours, there is no compelling or credible evidence to support such a notion; And as the borders of our knowledge of our surroundings is expanded, the reasons for having a god in the first place become superfluous.
So I disagree with this statement of yours;
"atheism comes from a belief that there is no god"
But agree with this statement
"Atheists find the concept of a god unbelievable" and would extend it to include "because despite thousands of years of worship, there is no compelling evidence to support the idea of a god".
As to why we debate = Some of us are naturally argumentative. Some will have personal or family issues, caused, in their minds, by this faith.Most debate the issue because along with the personal worship comes a raft of cultural baggage that intrudes into our daily lives, often to the detriment of the culture. Interpretations of religious screed and the pronouncements of holy men are used to justify a whole range of negative acts, to pass new or to enshrine old law that is unjust or supports inequality. The deleterious effects on humanity perpetrated by the zealous are only to obvious right now.
So- atheists have a legitimate interest in challenging the foundations of religious belief and the the legitimacy of the cultural restrictions they often endorse.
And the debate is not just for the people involved either; there is potentially a wider audience who are interested in the argument, but do not necessarily wish to contribute. And certainly I rarely initiate a debate on what I see as the shortcomings of religions faith, unless it is to comment on a story that illustrates these issues; Parents in America currently on trial for the murder of their son, who died of a perfectly treatable disease; This despite having lost a son just 2 years ago for the same reason, and being told by the court that they had to seek medical attention for their other children. All because of the parents faith.
I will however respond to posts, like goodlifes, for instance, that is just thinly disguised propaganda and evangelising; Especially since it is not even original work of theirs, but cut and pasted wholesale from the Watchtower archives.
And if those of a religious persuasion wish to receive only responses from the religious, they can request it in their OP, and I would usually respect that request - but remember this is an open forum, and we all have to live in the same world. We have to put up with the cultural consequences of religious belief, whether we believe in the same god, or none.
Belief and Intelligence. I do not assume a lack of intelligence amongst those with a religious belief. I simply think that, on this specific issue, the faithful are irrational in their belief. That does not mean, either, that I think them irrational about everything, unless their religious faith is so central to their life that it guides what they do.
That having been said - there are a number of studies which show an inverse link between religiosity and intelligence and religiosity and educational level, and religiosity and level of scientific knowledge; The trend is that, the higher your educational achievement, the greater your scientific knowledge, particularly biological science, or the greater your native IQ, the less likely you are to have a belief in a god....