I was an atheist and despised religious folk so much that I decided to read the Bible (cover to cover) so I would be better armed to ridicule them.
It was the eventual realisation that what I was reading was true, that was God's way of calling me.
Please do not think atheists stupid because they don't believe what we do. They are capable of living happy lives. To be honest, on average, I expect non-believers are more intelligent. I've met or interacted with plenty of dumb Christians
Of course intelligence does not make one correct. The truth makes one correct.
Both sides and even sub-groups within each side hold very firm to their beliefs on the whole.
Do not expect to argue a non-believer into believing in God.
Think of it this way - would you put aside your beliefs if someone laid out facts that showed you God was improbable? Of course not. You would ignore some of the statements and find some way to hold onto your faith. It works the same way around - if you put forward a strong case for God it won't matter - they will hold on to their beliefs just as strongly.
In the Bible the gospel was told to people who believed in God or gods. There just weren't atheists about in those days.
Today the 'target audience' for both sides should be the unsure or those searching for answers.
Atheists (and those that we disagree with who are Christians) are people the same as us. They come to their beliefs and seriously believe they are right. There is little point repeatedly attacking the other person or their argument, getting more and more irate with each repetition. And little point listening to their repeated barrage. Listen (or read) once and if it so affronts you, don't continue.
There should be no place for hate.