The chosen people had sinned. Thereby, they had been defeated, debased, and exiled. Jerusalem, its Temple, and the people's lives were in ruins. After generations of degradation, the people could hardly conceive of anything but further devastation.
Possibly you understand too well the condition of the chosen people at the time of the prophet Zechariah. Maybe your life has been one mess after another. Nevertheless, the Lord promises you, as He promised Jerusalem: "I will be for (you) an encircling wall of fire, says the Lord, and I will be the Glory in (your) midst" (Zec 2:9). The Lord is going to protect you and even surround you with His fiery presence. No longer are you going to be marauded, trampled, used, and abused. Your future is to live in God's glory and not in sin, slavery, defeat, shame, and self-hatred.
Therefore, "sing and rejoice...See, I am coming to dwell among you, says the Lord" (Zec 2:14). "Fear not, you shall not be put to shame; you need not blush, for you shall not be disgraced. The shame of your youth you shall forget" (Is 54:4). "No more shall men call you 'Forsaken,' or your land 'Desolate,' but you shall be called 'My Delight,' and your land 'Espoused.' For the Lord delights in you" (Is 62:4). Alleluia! Thank You, Jesus!