Come now, you who say, “Today or tomorrow we will go into such and such a town and spend a year there and trade and make a profit”— yet you do not know what tomorrow will bring. What is your life? For you are a mist that appears for a little time and then vanishes. Instead you ought to say, “If the Lord wills, we will live and do this or that.” As it is, you boast in your arrogance. All such boasting is evil. So whoever knows the right thing to do and fails to do it, for him it is sin.
Should we make plans? Yes, we should, it tells us right there “you ought to say.” We make plans, but we trust the Lord. You shouldn’t live your life being tossed back and forth, you need goals, you need direction. This is the right thing to do. So, now we know. Sin is not just what we do, it’s also not doing the right thing. Sin is very tricky… that’s why we can never master it. Trust in the Lord.