In order to understand two themes in today’s reading, we must go back to Revelation 7. Until that chapter, God had placed His “seal” only on a scroll. But now 144,000 sons of Israel are “sealed” - 12,000 from each tribe (7:3-8).
Yet John only hears this number. When he looks up, he sees a different image, much like Revelation 5 (see June 3), when John heard of the Lion of Judah, but when he looked up, he saw a Lamb that had been slain.
Here again the dueling images picture one thing: the people of God, united together, Jew (7:4-8) and Gentile (7:9), in Christ (7:10). This “great multitude” of Gentiles comes “out of the great tribulation” (14). For the second time we see that John envisioned Christians in the Tribulation.
Their primary characteristic is purity: twice John says the disciples washed themselves white, in the blood of the Lamb (14). This purity is the difference in the judgments in chapter 9. Those who had the seal of God on their foreheads were spared (9:4), but those who did not repent were not spared (9:20-21).
This brings to mind John’s earlier statement in his gospel, that salvation is by faith alone, but man is judged by his works:
John 3:35–36 (ESV): 35 The Father loves the Son and has given all things into his hand. 36 Whoever believes in the Son has eternal life; whoever does not obey the Son shall not see life, but the wrath of God remains on him.