An old story has resurfaced - The devil is having a big sales in his store of evil tricks. Everything has a price except for one box that has no price that. It is not for sales.
After almost everything has been sold, his demonic assistant asks him about what is in the box without a price.
The old devil whispers, "It's Discouragement! When all temptations fail, I have this box of potent tricks to use! I have more success using these against the Christians than any other tricks! Once hit, few have the strength or wisdom to rise to their former glory. Many just become mediocre and die fruitless! Isn't that great!"