(2) And I saw what appeared to be a sea of glass mingled with fire—and also those who had conquered the beast and its image and the number of its name, standing beside the sea of glass with harps of God in their hands.
A sea of glass was seen in an earlier vision (see comments on 4:6). It corresponds to the bronze laver, which was a model of baptism. Earlier, the sea of glass was seen in God’s heavenly temple, and its waters were as clear as crystal; all who are of the royal priesthood of Christ have passed through these pure waters. In contrast, we now see “a sea of glass mingled with fire.” It is still a model of baptism, yet not water baptism, but the baptism of fire. This is what John the Immerser warned the Jews about, saying,
“I baptize you with water for repentance, but he who is coming after me is mightier than I, whose sandals I am not worthy to carry. He will baptize you with the Holy Spirit and fire. (Matthew 3:11).
The promised coming of the mighty Savior would bring more immersion; one is the immersion of the Spirit unto salvation; the other is the immersion of fire, and that can’t be a good thing! To further explain the baptism of fire, John said,
“His winnowing fork is in his hand, and he will clear his threshing floor and gather his wheat into the barn, but the chaff he will burn with unquenchable fire.” (Matthew 3:12).
To the disobedient house of Israel, the Lord will deal with them as a harvester (consider the connection to Revelation 14:17-20), separating the good food from the bad, and baptizing the bad with unquenchable fire. This figure of the bronze laver as “a sea of glass mingled with fire” is an unmistakable sign of the Lord’s judgment against the Jews of the first century.
“So that the blood of all the prophets, shed from the foundation of the world, may be charged against this generation, from the blood of Abel to the blood of Zechariah, who perished between the altar and the sanctuary. Yes, I tell you, it will be required of this generation.” (Luke 11:50-51).
“Standing beside the sea” are those who have “conquered the beast and its image and the number of its name,” that is to say that they are the faithful Christians who did not turn to idolatry (spiritual harlotry) as Israel did. These stand as witness to the prosecution of the Jews, for they overcame when Israel gave in. And the Jews could not say that it was not possible to be faithful, for this multitude which stands beside the sea of glass are a testament to the fact that faithfulness is possible.
“With harps of God in their hands.” These are the harps of prophecy that we see three times in the book (see comments on 5:8). Whenever the harps are brought out, someone is about to prophesy through praises to God, just as David often did. Many of David’s psalms prophesied with harps of the coming Messiah and of the glorious Zion that he would restore.