"the marriage of the Lamb" has been delayed because "His wife has [not] made herself ready"

If "the marriage of the Lamb" has been delayed because "His wife has [not] made herself ready" (Rev. 19:7), what can we do about it? If "the Lamb's wife" is the New Jerusalem, the Holy City in heaven [21:9, 10ff.], how can we make it "ready"? It's beyond us; forget it, go back to sleep.
When the angel told John, "Come, I will show you the bride, the Lamb's wife," he gave him a panoramic view of the city. It had "a great and high wall with twelve gates, ... twelve foundations, ... the city was pure gold, ... the twelve gates were twelve pearls, … the street of the city was pure gold" (21:9-21). Even for angel architects and heavenly construction workers, "making" such a "city" "ready" could be a big job. Paving Main Street with gold, for example, must take time. Is that what has delayed the coming of Christ? If so, go back to sleep.
The "city" is real, very real; and its material construction was probably completed long, long ago. But what is the real "city"? Why is it called the "NEW Jerusalem"? The "Jerusalem" that crucified Jesus was the old one. When He addressed the old "city," sobbing like His heart would break, "O Jerusalem, Jerusalem, the one who kills the prophets and stones those who are sent to her! ... Your house is left to you desolate" (Matt. 23:37, 38), was He speaking to the cobblestones in the pavement, the timber in the gates, or was He addressing the people, inhabitants of the city?
The inhabitants of the New Jerusalem are described in Revelation 14:1-5 as "the ones who follow [not rebel against] the Lamb wherever He goes. ... They are without fault before the throne of God." These same "ones" have "washed their robes and made them white in the blood of the Lamb" (7:14). This is character-cleansing--accomplished by grace through the faith of Jesus.
When He died on His cross and cried out, "It is finished!" Satan was forever defeated, the great controversy won. But after 2000 years Jesus must also say that His seventh of the seven churches is "THE one" of all history that doesn't know it is "wretched, miserable, poor, blind, and naked" (3:17). Yes, she has something to do to "make herself ready for the marriage of the Lamb." We must wake up.