5 Be free from the love of money, content with such things as you have, for he has said, “I will in no way leave you, neither will I in any way forsake you.”  6 So that with good courage we say,
“The Lord is my helper. I will not fear.
What can man do to me?” 
Matthew Henry's Commentary on Hebrews 13:5-6
Commentary on Hebrews 13:1-6
(Read Hebrews 13:1-6)
The design of Christ in giving himself for us, is, that he may purchase to himself a peculiar people, zealous of good works; and true religion is the strongest bond of friendship. Here are earnest exhortations to several Christian duties, especially contentment. The sin opposed to this grace and duty is covetousness, an over-eager desire for the wealth of this world, with envy of those who have more than ourselves. Having treasures in heaven, we may be content with mean things here. Those who cannot be so, would not be content though God raised their condition. Adam was in paradise, yet not contented; some angels in heaven were not contented; but the apostle Paul, though abased and empty, had learned in every state, in any state, to be content. Christians have reason to be contented with their present lot. This promise contains the sum and substance of all the promises; "I will never, no, never leave thee, no, never forsake thee." In the original there are no less than five negatives put together, to confirm the promise: the true believer shall have the gracious presence of God with him, in life, at death, and for ever. Men can do nothing against God, and God can make all that men do against his people, to turn to their good.