More quotes by William Peter Blatty, The Exorcist

"As far as God goes, I _am_ a nonbeliever. Still am. But when it comes to a devil---well, that's something else."
"Perhaps evil is the crucible of goodness... and perhaps even Satan - Satan, in spite of himself - somehow serves to work out the will of God."
"We mourn the blossoms of May because they are to whither; but we know that May is one day to have its revenge upon November, by the revolution of that solemn circle which never stops---which teaches us in our height of hope, ever to be sober, and in our depth of desolation, never to despair."
"The child was slender as fleeting hope."
"God never talks. But the devil keeps advertising, Father. The devil does a lot of commercials."