I'm past the stage that I need to create arguments against Christianity.
But this argument doesn't shut them up, it simply gives them the opportunity to expound upon Gods love of man and his willingness to send his "only begotten son" to die for our sins. The power of his forgiveness is total they say, and it's evidenced by this event.
Trying to use reason against faith is unproductive and will often make you the target of ridicule and attack. Just let sleeping dogs lay when you're around them, it won't make you any less of a person.
"People who harbor strong convictions without evidence belong at the margins of our societies, not in our halls of power. The only thing we should respect in a person’s faith is his desire for a better life in this world; we need never have respected his certainty that one awaits him in the next."
- Sam Harris