To him it is sin...

"Therefore to him who knows to do good and does not do it, to him IT IS SIN." James 4:17

Often I think to myself, that though there are many bad things I could do, if I don't do them, then I'm doing well, then I'm pleasing God.  But if I strive to not do something, but don't replace that time and energy with something else, then I'm still wasting my time.  Even worse than just "wasting time"...it is sin! 
That really changes your way of looking at what you do with your time, that is, if you actually let yourself consider it. When the thought comes into your mind of a good thing you should do (whether it is check the laundry, give your family member a hug, tell that neighbor about Christ) it's not just NOT doing something good, it is sin. 

"So then each one shall give an account of himself to God!" Rom. 14:12

I'm afraid that this is an area I am often guilty in, and these things will be on my record before Christ at the judgement seat.  I would be sorrowful indeed, if the Lord were to say to me, "Well done at what you actually did, but look at all the things I gave you opportunity to do that you did not choose to do."
When we choose NOT to do a good thing, we do a wrong thing.  Choose wisely.