I here draw five morals concerning how atheists and the religious might usefully approach each other in debate and argument (this is adapted from a draft book chapter).
1. There's a tendency among the religious to take offence at comparisons drawn by atheists between religious belief and other supernatural beliefs such as belief in ghosts, fairies, etc. No doubt some atheists do just want to belittle and bait the religious by making such comparisons. However, it seems to me that drawing such a comparison can be very appropriate. I certainly intend no offence by drawing it. I don't think the religious should take offence.
2. Atheists should not suggest that religious folk are stupid. Unfortunately, many do. While there is some evidence that a lower IQ correlates with increased religiosity, the fact is that most popular religions – even the most absurd – can boast adherents at least as smart as myself. I count among my close friends Christians with impressive intellects. They aren't fools.
Note, however, that establishing that many smart, college-educated people believe something does not establish that the belief itself is reasonable. Young Earth Creationism is scientifically absurd, yet it has many smart, scientifically literate defenders, including some with tenured university positions. Indeed, it appears to be a feature of religions that they can seduce many smart, educated people into supposing even ludicrous falsehoods are reasonable. Consequently, religious folk should gain little reassurance from the thought that there are many smart, college-educated people who believe the same as them (unfortunately, many do).
3. I suggest honesty is the best policy. Christians who think the sin of rejecting God is so momentous that atheists deserve to burn in hell ought not to attempt to hide that opinion for fear of causing offence. First off, most atheists have thick skins. We know we're a highly distrusted minority (more Americans would rather have a pot-smoking President than an atheist one, for example). Secondly, I for one would much rather understand what my intellectual opponent really believes about me than have them disguise it. After all, if a Christian really believes that, as an atheist, I am hell-bound, they surely have a moral duty to warn me. I understand and appreciate that. I think we atheists should be similarly honest. I consider Christian belief of the sort defended by many mainstream Christians to be pretty ludicrous: scarcely less ludicrous, in fact, than many other religious belief systems that such Christians would probably find ludicrous (such as Mormonism and Scientology, for example). I think I should be honest about that, rather than disguise my opinions for fear of ‘causing offence’. For obvious reasons, dialogues between belief systems where the participants try to disguise their beliefs and deal in half-truths are unlikely to be helpful in terms of getting at the truth. Nor am I convinced such deceit is even the best policy when the aim is merely getting along. If my Christian friend Peter tells me he believes that, being an atheist, the depth of my moral depravity is so deep as to qualify me for eternal damnation, I'll be a little shocked. But I'll be happy to discuss that with him. If, on the other hand, he chooses to hide this assessment from me, then there is a good chance that I'll nevertheless detect his attitude. If you'd feel sullied after having shaken hands with a mass murder like Pol Pot, imagine how sullied Peter may feel after shaking hands with me. I doubt Peter could keep such moral revulsion entirely under wraps. And my detection of his deceit is, in turn, likely to make me suspicious and distrustful of him.
4. A little mockery and leg-pulling is, in some circumstances, entirely appropriate. No one should abandon a belief because others laugh at it. Nor should any religious person or atheist be mocked merely to cause them distress. However, while humour should not take the place of rigorous criticism, it can enhance the latter's effectiveness by breaking the spell of deference and ‘respect’ that belief systems are capable of casting over us. In Hans Christian Anderson's The Emperor's New Clothes, the small boy who points and laughs breaks the spell: he allows everyone else watching the naked Emperor to see how they have been duped, to recognise the absurdity of their situation. Of course, some authoritarians (be they religious or atheist) who revel in pomposity and demand overweening respect are aware that humour can unmask them, which explains is why they are particularly fearful of it (I am now thinking of Charlie Hebdo). I am more than happy for others to pull my leg. I hope they won't mind if I sometimes pull theirs.
5. Atheists should understand the often good motives of those who evangelize. After all, Christian evangelists really are trying to save us atheists. The stakes couldn't be higher. If I could only save someone from a dangerous fall by rudely grabbing them and shouting my warning in their face, I would. I will generally forgive those who strive, by behaving with similarly urgency, to save me from a fate literally worse than death. I certainly don't expect the religious to keep their beliefs to themselves.