Okay, here we are! Now, this world is isn't terribly different from our own. We live in a world governed by natural laws, where blessings (effects) are obtained by obedience to laws upon which those blessings are predicated (causes) - see D & C 130: 21. Let's seek to place Christ and Satan where they belong in the selfless-selfish spectrum in this world based on a cause-effect principle.
Effects: possesses all knowledge, all power, an eternal weight of glory, the worshipful adoration of trillions of humans, the constant company of God, boundless possessions, exaltation, peace, and a fullness of joy.
Causes: fidelity to God's will, including performance of the Atonement and every other task God laid upon Him
Effects: eternal damnation, eternal misery, the company of the damned, a day-to-day waking experience of ceaseless kicking against the pricks, without hope of offspring or glory
Causes: beguiling Eve, advocating his own plan in the Council in Heaven, disobeying God whenever he's not compelled to comply, tempting mankind to sin
Now we have juxtaposed Christ and Satan on an individual interest cause-effect criterion (how selfish they are as measured by effects on their individual welfare). This placement is necessary but insufficient to our placing them on a selfish-selfless spectrum, though, because the measure of selflessness must be against the interests of others.
The actions of both Christ and Satan make your and my salvation possible. Both are actual causes of human salvation (for background about actual cause and related issues, see http://en.wikipedia.org/wiki/Proximate_causation or http://en.wikipedia.org/wiki/Causality). However, it is clear that the actions of each led to different results for the individual actor. Satan's involvement, though necessary for the effect of the Fall (which is in turn absolutely essential to the salvation of man) and the reality of continuing opposition (see 2 Nephi 2:11-17, also the problem of evil and thoedicy), seems to have rewarded him eternal damnation in exchange for his efforts. Yet Christ's efforts, which are neither more nor less essential for the salvation of man than Satan's, are rewarded by the greatest power and possessory interest a selfish individual could hope for.
"He that findeth his life shall blose it: and he that closeth his dlife for my sake shall find it" (Matt 10:39. See also D & C 98: 13 and TG: self-sacrifice).
Selfishness: "that supreme self-love or self-preference which leads a person to direct his purposes to the advancement of his own interest, power, or happiness, without regarding those of others."
Sacrifice: To forfeit (one thing) for another thing considered to be of greater value.
It's interesting that sacrifice is defined and thought of as forfeiting A for B, where B is considered to be of greater value. To me, that "sacrifice" = "a great bargain." It's like exchanging 5 bucks for a 2010 Mustang V6 Convertible. What kind of a sacrifice is that? If sacrifice is instead more of a bad bargain, say, a person sacrificing his or her life so someone else can have the right to vote on whether or not to have a burrito or a taco, then we attain an upleasant deduction. Satan is far and away more selfless than Christ as measured only by effects. His actions, actual causes of our exaltation, benefitted us greatly while resulting in unending personal punishment for him. He made a truly "bad bargain" on our behalf. Christ's actions, also actual causes of our exaltation, also benefitted us greatly, but resulted in a gargantuan ROI (Return On Investment) for Him.
So now we've placed Christ and Satan on our contrived selfless-selfish spectrum. Where we to follow Satan's selfless example, we'd likely behave quite differently- for example, by setting up a regional kindergarten conference and then blowing up the session once all the kids arrive. [God's work is to bring to pass (presumably, maximize) the immortality and eternal life of man. Immortality for all mortals is already assured, leaving only eternal life to maximize. Protected class #1- all children who die before they arrive at the years of accountability are saved in the Celestial Kingdom - D & C 137:10 - which salvation is equivalent to eternal life. So if you slay 100,001 kindergarteners you damn yourself but bring about the net eternal life of 100,000 souls (100,001 guaranteed saved minus one soul unequivocally damned). Now that's selfless in effect both of helping God in his work and maximizing the benefit of your fellow man.]
In fact, God may have pursued a comparable mechanism until the recent decreases in childhood mortality. [1) "The Lord takes away many, even in infancy... instead of mourning we have reason to rejoice as they are delivered from evil." 2) "The only difference between the old and young dying is, one.. is freed a little sooner from this miserable wicked world." (Joseph Smith, Documentary History of the Church 4:553-554). 3) During ancient times and the Middle Ages, the infant mortality rate was about 200 deaths per 1,000 live births and the under-5 mortality rate was about 300 deaths per 1,000 live birth- http://en.wikipedia.org/wiki/Infant_mortality#Infant_mortality_throughout_history. 4) History of human life span and mortality
Or, we might set up an arrangement to join one of the other two protected classes: #2 millenial children or #3 Christ. [As essential as mortality is to our becoming gods, Jesus somehow achieved the desirable Godhood status before He ever came to earth- why not just follow His lead and skip the salvation-risky mortal experience? Or why not have everyone be born in the millenium- D & C 45:58 "And the aearth shall be given unto them for an binheritance; and they shall cmultiply and wax strong, and their dchildren shall egrow up without fsin unto gsalvation.]? These three classes are guaranteed salvation with no risk of damnation, whereas the rank and file participants on fallen earth may or may not end up receiving salvation.]
It seems that selflessness and rational self-interested behavior are more different- or more similar- than they superficially appear.
1) God commands that you seek your own self-interest. It's simply the ironic reality that to do so is, counter intuitively, to seek in the short-term the interests of others.
2) I feel to be grateful for my mortal experience notwithstanding my failure to make one of the three protected classes above. All of God's mysteries are accessible to me, and He will reveal them based on the pattern evidenced in 1 Nephi 11:1.