Luke 15

"As long as you are trying to earn your salvation by controlling God through goodness, you will never be sure you have been good enough for Him. You simply aren't sure God loves and delights in you. What are the signs of this lack of assurance? We have already mentioned one sign: Every time something goes wrong in your life, you wonder if it's because you aren't living right in this or that area. Another sign is that criticism from others doesn't just hurt your feelings, it devastates you. This is because your sense of God's love is abstract and has little power in your life, and you need the approval of others to bolster your sense of value. You will also feel irresolvable guilt. When you do something you know is wrong your conscience torments you for a long time, even after you repent. Since you can't be sure you've repented deeply enough, you beat yourself up over what you did. But perhaps the clearest symptom of this lack of assurance is a dry prayer life...Why is it so important to know that Jesus exposes elder-brother lostness as being as wrong and destructive as younger brother lostness? The elder brothers of the world desperately need to see themselves in this mirror...The younger brother knew he was alienated from the father, but the elder brother did not. That's why elder brother lostness is so dangerous. Elder brothers don't go to God and beg for healing from their condition. They see nothing wrong with their condition and that can be fatal. If you know you are sick you may go to a doctor; if you don't know you're sick you won't--you'll just die...In this parable Jesus says to us, 'Would you please be open to the possibility that the gospel, real Christianity, is something very different from religion?'...There is a big difference between an elder brother and a real, gospel-believing Christian. But there are also many genuine Christians who are elder-brotherish...While most people do not arrive at these extreme places, each approach (younger and elder-brother) to life has the seeds of its own destruction in it, which draws its adherents toward the spiritual destinations [Jesus] describes so well...He has vividly portrayed both of the world's two spiritual paths (rebellion and moralism)....However, he exposes them both as profoundly mistaken, as dead ends. He clearly wants us to take some radically different approach, but what is it? Where do we find it? We will find the answer when we realize that Jesus deliberately left someone out of this parable. He did this so that we would look for him and, finding him, find out own way home at last."

--Tim Keller, The Prodigal God p. 63-66, 69-72