After this I looked, and behold, a great multitude that no one could number, from every nation, from all tribes and peoples and languages, standing before the throne and before the Lamb, clothed in white robes, with palm branches in their hands, and crying out with a loud voice, “Salvation belongs to our God who sits on the throne, and to the Lamb!”
(Revelation 7:9-10 ESV)
Horatius Bonar (1808—1889) comments on this passage:
This is not the harvest of Israel, but of the world. The word has gone out from Jerusalem into all the earth. All nations hear the gospel, and some out of each of them obey it, and turn to the Lord. Every people furnishes its quota to this great assembly; every tribe has its representatives here; every region, every color, every language, every kingdom, every people, every age and century. It is the general assembly and Church of the First-born. How various the company in face, in speech, in manners, in dress, in habitation! Here all nationalities meet in one great heavenly nationality—without jealousy or distrust—all one in Him who redeemed them by His blood! Now it is seen that God has made of one blood all nations of the earth, and that under the shadow of the one great Sacrifice all these find shelter—sinners, yet pardoned—lost, but saved—vile, but washed white in the blood of the Lamb!