This verse has been given to me by many, many people. I consider our present sufferings are not worth comparing to the future glory that will be revealed in us. I called this the feel crappy verse, because when I first read it, I thought it was saying that even though you suffer and feel crappy, persevere because heaven awaits.
I was a little off the mark.
Of course, it would be folly to think that I could know exactly what Paul is trying to say here, but I am fairly sure he isn’t really focusing on the future – it’s the present upon which he’s fixated. When I look at this verse now, for some reason it reads as, “Don’t treat your present condition as suffering, but dwell in the glory of God.” Be joyful, because no matter the circumstance, God is infinitely greater; no matter the sin, God is that much more righteous. Even if you stacked up all the sins and sufferings of this world and put them next to God, there’s no way to compare them. Why are you downcast when God is on your side?
So it’s not the promise of heaven that spurs us onward, but it is the immense greatness of God that gives us joy NOW.