‘The ministration of death’ certainly was glorious, not because it could save but because it was from God. When God gave his law it was given with a tremendous display of divine power.
Now this is relevant today because every religious viewpoint outside Bible Christianity is like that, it is a works religion. Take Catholicism. It is supposed to be Christian, but as far as personal salvation is concerned, it is works: what the church does for you, and what you must do, and you must earn your salvation at the end of the day. It is not free salvation. Islam, it is works, we can do it. We can tithe a little and we can go through all the motions and the ceremonies of the daily routine and services, and we believe these things, that we can obey the law of God. It is religion which belongs to the Old Covenant not the New Covenant.