Sin is like smog
I live in the LA area, so I know all about smog. I was born and raised here, so I remember when the air quality was actually worse than it is now (thank you, emission standards!). But still, we do have some pretty smoggy times down here.
A few years back, I was in a bible study, and we were talking about sin, and the insidious nature of it, and how it can ensnare us so easily, without our truly realizing what is happening. Over the course of the conversation, I came up with an analogy that is straight from the LA basin.
We have local mountains here that rise very high very quickly, so you can go from tanning at the beach to skiing down the slopes in one day and still have time for a movie and dinner back home. This also means that you can see the "lowlands" clearly on your descent from the mountains. On most days - especially if you are heading down in the afternoon - you see a striking scene: where you are, there is a clear blue sky, and visibility for miles and miles. Where you're heading, there is a solid light-brown sea of smog. You can't see the lowlands through all the smog. It looks like fog, or cloud cover when you are flying, but it is really, truly, smog in the LA basin.
Yuk.
Your first thought is always the same: no way am I going down there! I will die a horrible, choking death is seconds. But, you head down anyways, because that's where you live.
Now, here's the other striking thing: you never hit the smog.
You get home, and things seem just like you left them. You are breathing just like you did yesterday, and the day before.
So what happened to the smog? It's still there, it's just that the descent into it was so gradual, that you didn't even realize when it happened. Your body adjusted, your eyes adjusted, and all seemed normal.
This is what sin is like. Very seldom do we jump from the clear air of purity into a thick, globular morass of sin. Usually, we subtly, slowly ease into it without truly realizing what we are doing. The air seems fine down here, thank you. Sin, what sin? Leave me alone.
Only when we are lifted back up into the pure air through repentance and forgiveness are we able to look down at where we were living, and see the "smog" of sin.
What are we to do? Repent early, repent often. Forgiveness is always waiting for you. You won't know how much you needed it until after the fact when you look back down.