There is an old Sanskrit saying which goes "Whatsoever a divine (living) being desires, that the living being becomes."
This does not mean that a passing yen for soft-centered chocolates is going to land you on a candy counter; but it does mean that whatever is the ruling desire of a man's life, the forcible urge that overrides all other considerations, will shape him and ultimately his destiny through eternity until the urge has run its course or been neutralized by an opposing current of equal strength. The annals of humanity teem with tales about men and women who have performed seemingly impossible feats simply because they wanted to so strongly that their desire ruled their entire living until the goal was attained. One who is willing to make any sacrifice for the acquisition of wealth can undoubtedly become wealthy, though often at the price of other riches of soul and spirit. One who strongly desires fame can achieve notoriety; such a desire being for acclaim rather than true fame.
Our actions are guided by desire always. The desire in turn is actuated by the mind; either by the personal mind which is at best calculating and shrewd, at worst vicious; or by the impersonal, spiritually guided mind which is unselfish because of its affinity with the universal spirit imbuing all beings.
We have a choice at every turn, every moment, and our desires fluctuate according as we are guided in our choice by the selfish or unselfish element in us; or by the 'lower' or 'higher.' We all know the superb simplicity of this obvious fact. Every smoker who has "given up smoking" knows that if you want to stop more than you want to smoke, you have no trouble stopping. But that if you want to smoke more than you want to stop, you cannot stop. This is a small and insignificant example, but it proves conclusively that what you want to do is what you will do.
Apply this simple fact to life in general. Does any man want to be the slave of a sort of personal isolationism, working for himself, loving himself, living for himself, ultimately dying by himself, bereft of all the sweetness of human relationships? That is an extension of a selfish impulse followed to its logical conclusion. Fortunately human beings contain an infinite agglomerate of selfish and unselfish motives, so that our flounderings between right and wrong bring no such direct results but only a mixture of joys and sorrows that we accept mostly without analysis. However, our zigzag course could be greatly straightened by a little attention to our current motives.
Ask these questions? Do I really want to become a better man? Do I really want to help to create true brotherhood among men?
John Doe unhesitatingly answers: "Why, of course!" What he means is that some time in the vague future there will occur a splendid occasion when he will with one stupendous act of self-sacrifice, hopefully to be recorded in story and song, arise and save humanity with one sweep of his mighty arm.
What he does not recognize, or forgets, is that his work will be slow, unnoticed, humdrum and infinitely tiresome, day after day, year after year, until his life ends without his even knowing what the result of his efforts has been.
(From Sunrise magazine, May 1953; copyright © 1953 Theosophical University Press)