If you email your reason against Christianity to defeating100reasons AT gmail DOT com then it might get selected for a “from the mailbag” response. I’ll probably pick 10 emailed reasons to help make up the 100. I’ll either choose from several popular related questions or good and interesting unique, particular questions. Completely obscurantist objections will probably not be selected. These ‘reasons’ do not to be yours, it can simply be one you’ve heard and wondered about.