Numbers 32:23 — But if you do not do so, then take note, you have sinned against the Lord; and be sure your sin will find you out.
 
Do you have sins that you cannot hide? I do. Anyone who sees me can tell, without needing to make inquiries, that I have not taken proper care to balance my diet and exercise!
I’m sure that when I was a child somebody must have given me the warning that Moses gave the Rubenites and Gadites — because I had plenty of things I thought I could get away with until I found differently.
King David certainly felt the force of the lesson too. When he committed adultery with Bathsheba he might have thought he could get away with it … until her belly started to provide some irrefutable evidence, and drove him to the horrific further sin of arranging the murder of Uriah the Hittite.  
There are some sins that seem easier to hide. There’s laziness for instance. It’s not always obvious that somebody isn’t working as hard as they should be – especially if they always seem to be in the right place at the right time. But Proverbs 6:10-11 warns “Yet a little sleep, a little slumber, a little folding of the hands to sleep: So shall thy poverty come as one that travelleth, and thy want as an armed man.” It might seems as though slacking off a little, “just  bit, for a little while”, might be OK – but people will notice your falling off, and consequences will follow. Or you might fall into sexual temptation. Oh, I don’t mean full on temptation like King David, but maybe watching the wrong movies, visiting the wrong websites … “There’s no harm in that”, you might think, “it’s only me involved.” Sadly that’s a dangerous self-deception. There’s a reason Psalm 101:3 says “I will set no wicked thing before mine eyes: I hate the work of them that turn aside; it shall not cleave to me.” The eyes are the gateway to the mind and heart. What we read and see influences our attitudes — and sooner or later those attitudes affect the ways we treat other people. The change in you will be noticed!
There is a potential upside to all of this, though. There’s another text  — Galatians 6:7-8 that says “Be not deceived; God is not mocked: for whatsoever a man soweth, that shall he also reap. For he that soweth to his flesh shall of the flesh reap corruption; but he that soweth to the Spirit shall of the Spirit reap life everlasting.” It certainly repeats the warning, but there’s a promise too: “he that soweth to the Spirit shall of the Spirit reap life everlasting.” The life of the spirit has everlasting fruit.