Tony Jones is a Christian theologian and he has started a series in which he tackles the toughest arguments against Christianity:
All the details on submitting your questions are here. Challenge him! Make him sweat!
… this series is for everyone who doubts. It’s for your friends who are agnostic and atheistic. It’s a place for them to email me a question, and get an honest answer — even if the answer doesn’t necessarily show Christianity in the best light. It’s a place for you to submit the biggest hurdle you have to fully giving yourself over to the Christian faith.