Now listen, you who say, "Today or tomorrow we will go to this or that city. We will spend a year there. We will buy and sell and make money."
References for James 4:13
You don't even know what will happen tomorrow. What is your life? It is a mist that appears for a little while. Then it disappears.
Instead, you should say, "If it pleases the Lord, we will live and do this or that."
As it is, you are proud. You brag about it. That kind of bragging is evil.
So when you know the good things you should do and don't do them, you sin.