Let the lowly brother glory in his exaltation, but the rich in his humiliation, because as a flower of the field he will pass away.
Believe it or not, that’s not a threat. It’s actually a promise. And I don’t mean that in the way that a parent tells their child, “I’m not threatening, I’m promising!” usually that deals with exercising authority. I don’t think that’s the case here. It’s just reality–men fade away, even the rich. James ends up talking about favoritism in chapter 2, about how people in the church are not to fancy those with nicer things, clothing, jewelry, etc.
I think the heart of what James is getting at here is having an eternal perspective. For the poor (lowly) man, he can rejoice in his exaltation through the gospel–that he is worth more than what he has, and that he is not confined or defined by that. That God doesn’t reserve any favor because of his social standing. He understands he has a treasure in heaven, and that’s worth rejoicing over.
On the other hand, the rich has achieved a status by one thing: either by hard work or by his name. Either he spent years building a fortune or else he inherited it from his family, as money tends to go.
That said, I think the important thing here is to balance perspective. As a rich person, humiliation is important because you begin to realize that:
Mercy isn’t something we are entitled to. It cost Jesus everything to live on a ball of dirt and resist temptation all of His life, to live perfectly, and to die at the hands of unjust men. Understanding what it cost Jesus is humbling and overwhelming.
On the other hand:
Mercy isn’t something you have to work for! You can work all you want, but it’s not helping you get any extra mercy, and it doesn’t earn you righteousness. Being willing to slow down and rest is extremely humbling.
The interesting thing about Christianity is that everyone has a past. What’s easy for one person to reconcile in their mind takes someone else years. a “poor” person may never struggle with feeling entitled, while a “rich” person may never struggle with feeling like a second class citizen. But the gospel makes everyone in Christ equal, and makes Jesus great. take that for what it’s worth.