The atheist professor of philosophy pauses before his class and then asks one of his new students to stand.
'Do you believe in God?'
'Is God good?'
'Sure! God's good.'
'Is God all-powerful? Can God do anything?'
He considers for a moment. 'Here's one for you. Let's say there's a sick person over here and you can cure him. You can do it. Would you help him? Would you try?'