Come now, you who say, "Today or tomorrow we will go to such and such a city, and spend a year there and engage in business and make a profit." Yet you do not know what your life will be like tomorrow. You are just a vapour that appears for a little while and then vanishes away. Instead, you ought to say, "If the Lord wills, we will live and also do this or that." But as it is, you boast in your arrogance; all such boasting is evil. Therefore, to one who knows the right thing to do and does not do it, to him it is sin.
Life is short; do what's right!
Your life may be shorter than you think. Even if you are a careful driver, the person who runs the red light and hits your car may not be. Or something could go wrong with your health. There are no guarantees. And even if you live to be old, you will feel that your life has flown by so fast.
Don't waste your life on insignificant things when there is so little life to be lived. Focus your time and energy and creativity on things that matter. When you "know the right thing to do", do it!
If you live for things that don't really matter, you are wasting what can never be retrieved. Make your life count.