This passage is just before the greatest of all moments in history, the moment when redemptive history reaches its culmination, the moment Jesus Christ returns in all His glory to the earth. This is the last of seven visions of heaven in Revelation. And we are ushered into heaven to hear the hallelujahs from the angels and all heavenly beings. This message is about why they are saying hallelujahs to our Lord and savior Jesus Christ.