i believe that it was cs lewis that said that sin was essentially doing or taking what God has already promised us outside of his timing-or something to that effect! or if you want to simplify even further, sin is doubting the provision and goodness of God. the entire bible is full of expressions of the provision of God and the promises of good things, but just a few:
psa 107:9 — he satisfies the longing soul, and fills the hungry soul with goodness.
mat 7:11; if you then, being evil, know how to give good gifts unto your children, how much more shall your Father which is in heaven give good things to them that ask him?
luk 1:53; he has filled the hungry with good things; and the rich he has sent empty away.
jam 1:5, if any of you lack wisdom, let him ask of God, that gives to all [men] liberally, and upbraids not; and it shall be given him.
jam 1:17; every good gift and every perfect gift is from above, and cometh down from the Father of lights, with whom is no variableness, neither shadow of turning.
and what was the sin of adam and eve but doubt of God's provision and goodness? so here in this parable you can see how the son demanded what his father had already promised him and more if he would just wait until the appropriate time. during the waiting the son would learn how to use his wealth wisely, to live prudently and honorably rather than indulgently and would no doubt enjoy the fruits of his patience for the rest of his life. he would also honor his father with his obedience and learn obedience. finally the reward would be greater simply because his fathers wealth would likely increase over time (especially with the added investments of his son). yet the son demanded his father to sacrifice by liquidating his inheritance-because it was probably tied up in property, animals, and other investments. it hurt the father and his brother and, in the not so long run, himself.
it seems a simple concept and so obvious when we see it illustrated in this story but in practice, this principle is not so black and white. it is so easy to justify our action and convince ourselves that we are not actually doubting the goodness of God, that we are not being impatient or disobedient, that we are not living indulgently but rather deserve what we take-that what we are doing is natural and human- that we are not cheating ourselves (a bird in the hand are worth 2 in the bush) that we are not hurting our loved ones our brothers and sisters and our heavenly father. its so difficult to see clearly through our emotions and through our human desires even when others point it out to us. clarity only comes from the Lord, and only when we are willing to hear it (or when that which we demanded too soon no longer sustains us)