Now we see, how many good things, interwoven, spring from the cross.  For, overturning that good opinion which we falsely entertain concerning our own strength, and unmasking our hypocrisy, which affords us delight, the cross strikes at our perilous confidence in the flesh. 
-John Calvin 
There is a story that goes something like this—This guy’s strolling down the street when he stumbles and falls into a manhole with walls so steep he can’t get out.  A doctor passes by, and the guy shouts up, Hey you, can you help me out?  The doctor writes a prescription, throws it down in the hole and moves on.  Then a priest comes along, and the guy shouts up, Father, I’m down in this hole.  Can you help me out?  The priest writes a prayer, throws it down in the hole and moves on.  Then a friend walks by and the guy excitedly shouts up, Hey, Joe, it’s me.  Can you help me out?  And the friend jumps in the hole.  The guy says, Are you nuts?  Now we’re both down here.  The friend says, Yeah, but I’ve been down here before—and I know the way out.
Jesus sensed that his disciples were having a hard time with this and said, ‘Does this throw you completely? What would happen if you saw the Son of Man ascending to where he came from? The Spirit can make life. Sheer muscle and willpower don’t make anything happen. Every word I’ve spoken to you is a Spirit-word, and so it is life-making. But some of you are resisting, refusing to have any part in this.’   (John 6:61-64a, The Message Bible) 
The King James Version of the Bible puts it maybe even better—the flesh profiteth nothing.
Think you can beat sin, handle temptation, master your lusts, and manhandle the Devil?  I tried, and my advice—don’t try it—there are some things not worth trying and destined to fail.