It also doesn't help that you get a lot of she-said-he-said in these sort of discussions. An atheist might critisise a theistic argument only to be greeted with the usual chorus of 'not all theists believe that'; ad hominem attacks meant for the fallacies of a particular atheist are used by a theist to apply to a whole group of them, in spite of the fact that individually, each person might hold to a different philosophy.*
The final straw came more recently, with the issue of wrong done by religious institutions, particularly on the charge that the spectacular cruelty exhibited by the religious in, for example, pre-Christian sacrifices, the Inquisition and the Wars of Religion etc etc is one only religion can boast of.
( And on she goes... )
Everyone please take note of the Medieval Review and the Classical Review. I am way lower in the rankings than even the most amateur of amateur historians but so far, thanks to these two services, I've learnt more about medieval women doctors, law-keeping (and making) in late Antiquity Russia, Political thought in Ancient Rome and acoustic science/philosophy in Classical Greece than I ever thought possible.