All of Christianity's claims hinge on one historical fact-- the bodily resurrection from the dead of a man, Jesus Christ.  If it's true, it changes everything and requires belief and repentance from every human being.  If it's false, then "your faith is futile and you are still in your sins" and Christians "of all people most to be pitied".

The author retraces his conversion to Christ by hunting down the historical evidence for the resurrection.