If you believe what God says about you, then you will live differently. Whenever you see sin, there is also unbelief. Real faith produces action. That is the message of James. It is that faith without works is dead.
Real faith is accompanied by works.
You can t see faith. You can only see that which accompanies faith. Paul has spent the last 5 chapters outlining God s plan of salvation. The only thing he has called his readers to do is to believe it. But now they are called to action.