I've had thoughts on why many cling on to religion, even after constant debunking and debating. I think I may have a possible reason why some do not give them up.
Most religions all have some system of an afterlife. People practicing the religion believe that, if they follow their specific book and appease to their specific God, they get to go to a magical place where nothing bad happens and they get to live out their wishes and desires that were either impossible in their mortal life, or there life was too short to live it.
When someone suddenly suggests that such a concept does not exist, the believer becomes defensive. Death is a bitter result of life. We dread the day we where we breathe our last breath, or if our life was suddenly cut short. To us, the concept of an after-life is comforting, a God protecting us like a Dad telling his son everything is going to be alright, even though he knows the bitter end is near.
I think, while not the sole reason for many that hold on to their faith, a denial of a mortal death being a permanent death is what keeps them from swallowing the bitter pill of reality that life is not fair, and that shit happens and you may not get to do everything in life or you could drop dead the very next day.
I was born in Mississippi, and raised Baptist, although, my family was mostly lazy Christians who only went to church on around the Holidays. I had the hope as a small child to go to Heaven and be with Angels and no kids there would ever be mean to me again. The thought that I couldn't have any of that would probably have scared me back then.
I came to realize that it's for the best that there is no afterlife. Imagine what exactly you would be doing in an afterlife. As the eternity went on, you would grow tired of the same mundane things. Would you truly want to spend your mortal life appeasing some God, only so you can appease him the rest of your life? I can't think of anything else that would be so...well, boring.
In a way, I feel more confident in this life. It won't be okay if I skip out on opportunities, because I may not get the chance again. This is my one shot, and I don't want to blow it on wishful thinking.
How about you? If you were once religious and now Atheist, how did you overcome the hurdle of accepting there is no afterlife? Or, do you not believe in an afterlife, but in some way, wish/hope there is one? Has any of this changed your perspective on how you live your life than how you lived your life beforehand?