The repeated use of the word holy shows that the Lord is completely set apart from all creation.
all the earth is full: The Hebrew text does not include a verb in this line. Because of this, translators understand the seraphim’s words in two possible ways.
The earth may already be filled with God’s glory through creation, even though sin has damaged it.
The earth may be filled with the Lord’s glory in the future, when he fully establishes his rule as King over the earth.
Both understandings point to the same truth. One day, the Lord’s glorious presence will be known more fully on earth. This will happen even though humankind is sinful and wicked nations are powerful.
God also revealed His glory in a greater way through the incarnation, when the Son of God became human (John 12:41; 2 Corinthians 3:18; 4:4–7).