For that person must not suppose that he will receive anything from the Lord; (ESV)
What a sobering thought. James speaks of those who will not receive anything from the Lord. We must ask, who is he referring to? The previous verse gives us the answer. James described the person who doubted the Lord. That person is the one who should not suppose that he will receive anything from the Lord.
As we discovered in the previous verse, God wants us to place our faith in his divine character. If we come to him while at the same time doubting that he is who he said he is, and that he is able to do what he says he can do, than the idea of receiving something from him would be an absolute absurdity.
I believe that one of the biggest problems in the Church at large is that we do not believe proper doctrine. We do not know what is true about God's divine nature. And if we do not know what is truth about God we certainly we will be full of doubt. Let's just consider a few things about God's nature that are important for us to not be doubters.
God is sovereign. We are not. Sounds simple, doesn't it? Yet, many people come to the Lord asking for things while they try to provide those things for themselves in their own efforts. God is good. You cannot complain that God is unfairly trying you and expect his deliverance. You are doubting his goodness. God exists for his own glory, not yours. You cannot come to the Lord demanding things that will build up your pride. You will not receive anything from him. Do not doubt God's own pursuit of his own glory. It is right and just for him to do so. He is perfect.
Come to the Lord, but check your doubts at the door of his throne room. If you believe wrongly about the Lord, you will not receive from him. Know the truth about his nature. Trust him.