The reason the writer to the Hebrews tells us to be content with what we have is that the opposite implies less faith in the promises of God. He says, “Keep your life free from love of money, and be content with what you have, for he has said, ‘I will never leave you nor forsake you.’ So we can confidently say, ‘The Lord is my helper; I will not fear; what can man do to me?’” (Hebrews 13:5-6).
On the one hand, we may trust in the Lord to be our helper. He will provide and protect. And in that sense there is a measure of prosperity he will give us. “Your heavenly Father knows that you need them all” (Matthew 6:32). But, on the other hand, when it says, “Keep your life free from love of money, and be content with what you have” because God promises never to leave us, it must mean that we can easily move from trusting God for our needs to using God for our wants.
The line between “God help me,” and “God make me rich,” is real, and the writer to the Hebrews doesn’t want us to cross it. Preachers should help their people to remember and recognize this line rather than speaking as though it weren’t there.