2 Corinthians 3:7-11
"Now if the ministry of death, carved in letters on stone, came with such glory that the Israelites could not gaze at Moses' face because of its glory, which was being brought to an end, will not the ministry of the Spirit have even more glory? For if there was glory in the ministry of condemnation, the ministry of righteousness must far exceed it in glory. Indeed, in this case, what once had glory has come to have no glory at all, because of the glory that surpasses it. For if what was being brought to an end came with glory, much more will what is permanent have glory."
When Moses came down from the mountain with the law carved in letters on the stone, the glory that shined forth from his face caused the Israelites to not be able to look at him, but his glory was the ministry of death and condemnation. It is not that the law was bad or that God made a mistake but that His work was not yet done. The law was sent forth to show our need for the Savior we have in Christ Jesus the Messiah. It was planned from the begininng to be "brought to an end" and be replaced by the ministry of the Spirit, which is life now, and forevermore.
So should not the glory, as a reflection of Christ's glory, shine from our faces in the same way? Should not people only be able to see the glory of Christ shining from our faces as the evidence of His Spirit living within us? I think the answer is a resounding yes! So why does this not happen? Why is Christianity just another part of the world that plays its role and blends in fine with everything else? I believe, as I have stated before, that we have lost the seriousness of our sin and the majesty of God's grace. Sin is incompatible with God, but thanks be to Him that he has given us grace to cleanse us of our sin, but that day has not yet come! We live in a world ruled by the the prince of the power of the air, and we must go to war against him daily! Our sin is forgiven but it has not yet been purged from our flesh. It is our duty, by the gifts of the Spirit, to mortify our sin.
To come back to the end of our passage, the glory of the law has passed away. It has been replaced by the surpassing glory of Christ and Him crucified, for which we have forgiveness of sin and access to life now and evermore. The law was passing, the law was not plan A and Christ plan B, it was meant to pass and Christ is now our permanence in life, love, and joy.