"There's no way I'm ever going to run a marathon, so I'm just going to sit on the couch and eat cheese doodles by the case load."
Sounds silly, right?
Yes, it does. It's also not even remotely an accurate comparison.
...But that's the either/or dynamic a lot of people in this thread are trying to offer us.
You see, the idea is that each of us should be trying to be better than we were before.
Define better.
It's understood that no one is perfect, but it's also understood that we can't use it as an excuse to stop us from trying.
At no point did I suggest we shouldn't try to sin less, or shouldn't try to be obedient to God.
But a proper understanding of the dichotomy between Law and Gospel ensures that we never deceive ourselves into thinking that we have somehow attained righteousness through our own efforts. Because such righteousness is not possible for sinners.
My spine may, for example, may be too messed up to let me do serious physical exertion, but I try to keep myself in at least good enough shape to where I can still work as a delivery driver as the paper needs me to. (The raw bundles of papers can be up to 50 pounds apiece, a respectable amount of weight.)
The question is not should we try to be faithful to the commandments of God, because of course we should. In fact it's not even an option, it's a command, "Do this". God doesn't ask, He commands that we love others.
The question is can we, as sinners, be righteous through our own ability as the Law commands us?
Because whenever I see people answer that question in the affirmative one several things usually happens:
1) God's Law is denied, and the commandments of God become more like helpful suggestions rather than absolute commands, I mean, sure God says I'm supposed to love my neighbor as myself, but isn't it enough that I at least make some sort of passing effort at being kinda nice to people?
2) We engage in a fun little game of cherry-picking commandments and also cherry-pick at our own sins. I mean, after all, I can't be that much of a sinner, it's not like I killed anyone.
3) Total delusion, as in, why yes I have become righteous, as long as I focus on how righteous I feel that's all that matters. And I feel pretty righteous, and anyone who is critical of my behavior or who tells me I'm sinning is an agent of the devil. I'm not sinning, I'm just making little mistakes.
4) Hopeless despair, I know I should be righteous because the Law tells me to be righteous, but I keep messing up. Why do I keep messing up? Maybe it's because I'm not saved, maybe it's because God doesn't love me, maybe it's because I haven't tried hard enough. But if nothing I do can make God love me more, if no matter how many times I try I keep failing--then what's the point? Maybe I am a hopeless lost cause and I should just give up.
Because here's something that never happens when someone thinks they can be righteous according to God's commandments--they actually become righteous. It doesn't happen.
At least number 4 starts to get us somewhere though, the first three are all pride. But at least with the fourth there's the realization that God's Law says "Do" but that I do not do it. The problem is leaving it at that. As though that's all there is: Law.
Because without the Gospel the Law is a death sentence. After all, the Light has come into the world, but men loved darkness more than light for their deeds were evil.
If we treat the Gospel as though it were just more law, then we not only don't preach the Gospel at all, but we are simply speaking more death. Death upon death, condemnation upon condemnation, sin upon sin. Preach more law, preach more death, preach more condemnation, and add sin to sin so that the sinner is even worse than he was before.
But preach the Gospel. I mean, the actual Gospel, and that's life. In fact it's eternal life.
-CryptoLutheran