Think about it: divinely inspired moral codes tell you to feel happiness by delving into your past accomplishments. They tell you: you didn't eat too much yesterday, you gave to the poor, you held less for yourself, and so on and so forth. You achieved so much, without realizing it, for you were focusing on the pain you were inflicting yourself the entire time.
The devil tells you to look into the future instead: how bountiful are the reward of those who steal, who commit sin against nature, who eats and drinks poison to obtain insight. When the time comes, the prize is not there, and you ponder:"Has it ever been there?"
Yet, I wonder, what does teach you of the pleasures of the present? Is the momentary pleasures of memory or flesh worth the toil?