Casting out demons

There is a strange overlay of patterns with Jesus’ view of those casting out demons in His name (in Matt. 7 and Mark 9), with the Cain and Abel story in Genesis 4.  There is an arbitrariness with which the Lord views their sacrifice. He does not say exactly why one is accepted and one is not—but He can smell the difference.  
Why are you angry? Why are you angry when your sacrifices in life are not accepted and your brothers’ are?  “Lord, Lord! Didn’t we…blah, blah, blah.”
“If you are good, will you not be accepted?”
“But if you are not good, then the idea of sin and sin-offering will be a creature that crouches at your door and desires to own you. But you can rule it.”
It does not matter whether I think the fruit of my labour is acceptable, it matters what God smells when it burns —when what I bring is exposed to judgment of heat and fire.
Oddly, frighteningly, the most important part of my action is not the result that I see, but the result that I don’t see—not the fruit that I produce, but how it tastes when it is consumed. I may cast out demons in Jesus’ name and still be just as  possessed—by “I”, by “My”, by my desires.  My sacrifice may be burnt on the alter, and the essence of my heart detected and rejected.