No I don't mean the Black Sabbath song (R.I.P. Ronnie James Dio)... Well, not exactly anyway.
Here is an old Zen story about a monk and a samurai. It goes something like this:
A battle weary samurai came to see a zen monk to ask him the difference of heaven and hell. To which the monk replied to him, "Why would I give a murderous bastard like you such precious knowledge? You are probably too arrogant and stupid to even comprehend something so profound. You're a maggot. No, you are even less than a maggot, you are samurai."
Samurai were never treated this way in ancient Japan, so he instantly felt his rage well up inside of him as he drew his razor sharp katana from its scabbard to cleave the monk in two.
But the monk never flinched, he merely said, "That, samurai, is hell."
Instantly the samurai understood the lesson and realized that he was going to kill the holy man because of his own ego tears filled in his eyes as he pushed his sword back into its scabbard and fell to his knees thanking the monk profusely.
"...And that," said the monk, "is heaven.