Revelation 5:9

And they sing a new song, saying, Worthy art thou to take the book, and to open the seals thereof, for thou wast slain, and didst purchase unto God with thy blood men of every tribe, and tongue, and people, and nation,

The glorious outburst in heaven extolled the triumphant death of Christ on the cross, that being where the purchase of a people from all classes and kindreds was actually paid. Very clearly, it is not some far-off millennial morning which is in view here but the scenes of Calvary, the garden of Gethsemane, and the post-resurrection meeting with the apostles in the upper room.

They sing a new song ... This is the new song of redemption in Jesus' blessed name, the "new song" prophesied by Isaiah 42:10. In this connection, it is proper to note that "forgiveness of sins" is the newest thing on the planet earth, being never before possible until the death of Jesus on the cross. See extensive discussion of this in my book entitled "The Mystery of Redemption." Christianity is the truly new thing. In it are the new creation, the new name, the new song, the new heaven and the new earth, the new birth, the new life in Christ, etc.

Strangely enough, the widespread references in sermonic literature to the "song" which the angels sang the night Jesus was born find their only corroboration in what is written here. This passage says "they sang a new song," introducing it by "saying." It is plain that this verb is consistent with song as well as speech?[40]

Purchase with thy blood ... The conception of the church as a possession, bought by the blood of Christ, is everywhere in the New Testament. "Ye are not your own; ye are bought with a price" (1 Corinthians 6:19,20). "The church which he purchased with his own blood" (Acts 20:28), etc.

Of every tribe ... tongue ... people ... nation ... The universal characteristic of the church is stressed by this. It is the church of our Lord Jesus Christ that actually concerns every man ever born on earth.