In his book, The Prodigal God, Tim Keller focuses on both brothers in Jesus' famous parable about the prodigal son. He argues well that Jesus in the parable is purposefully trying to represent the two main ways people decide to seek for meaning and happiness in life. One main way is by self-discovery and autonomy (represented by the younger brother). The other is by morality and being good and right (represented by the older brother). Keller writes,
"[There are] two basic ways people try to find happiness and fulfillment: the way of moral conformity and the way of self-discovery. Each acts as a lens coloring how you see all of life, or as a paradigm shaping your understanding of everything. Each is a way of finding personal significance and worth, of addressing the ills of the world, and of determining right from wrong" (29).
He then argues throughout the book that although they are two different ways of looking at the world, both are ways to live in defiance against God. People often just assume that the overtly sinning, rebel is the one against God, but as Keller shows, moral people can be just as much against God in their hearts:
"Religious and moral people can be avoiding Jesus as Savior and Lord as much as the younger brothers who say they don't believe in God and define right and wrong for themselves" (43).
Keller then brings it all together, showing that although most people acknowledge that Jesus doesn't allow for the Christian to sin and do whatever they like, most people miss that Jesus also strongly doesn't allow for Christianity to be a moralistic religion like many other faiths in the world:
"It is typical for people who have turned their backs on religion to believe that Christianity is no different [from other religions]. They have been in churches brimming with elder-brother types. They say, 'Christianity is just another religion.' But Jesus says, no, that is not true. Everybody knows that the Christian gospel calls us away from the licentiousness of younger brotherness, but few realize that is also condemns moralistic elder brotherness" (67).
It is good to remember that Jesus does not condone younger or older brothers. Both are ways in which people decide to snuff him out and live on their own. What he wants is our hearts turned back to him, looking to him to be our Savior and our Lord.
Quotes from Tim Keller, The Prodigal God, (New York: Penguin Books, 2008).