How do we know the doctrine of the Church being the Holy City is true?

The truth that the Church is considered the Holy City is firmly grounded in the revelations presented in Scripture. Revelation 21 uses rich figurative language to portray the Church not merely as an earthly institution but as the bride of Christ, adorned for her husband. This portrays an eternal relationship and covenant that God has established with His people. Additionally, doctrines such as the covenant of grace deeply support this view, asserting our identity as the New Jerusalem is based on divine grace rather than human merit.