John Calvin Commentary Romans 5:4

"and stedfastness, approvedness; and approvedness, hope:" — Romans 5:4 (ASV)

Patience, probation, etc. James, adopting a similar gradation, seems to follow a different order, for he says that patience proceeds from probation; however, the different meaning of the word reconciles both. Paul takes probation to be the experience that the faithful have of God's sure protection, when, by relying on his aid, they overcome all difficulties; even when, while patiently enduring and standing firm, they experience how much the Lord's power avails—the power he has promised to be always present with his people. James takes the same word to mean tribulation itself, according to the common usage of Scripture; for by these God proves and tries his servants, and they are often called trials.

According to the present passage, then, we make advances in patience as we ought only when we regard it as having been sustained for us by God’s power and, as a result, cherish hope for the future: that God’s favor, which has always aided us in our necessities, will never be lacking for us. Thus, he adds that from probation arises hope, for we would be ungrateful for benefits received unless the recollection of them confirms our hope for the future.