Isaiah 6 is a grand display of God’s holiness and how mankind compares to God. In this vision of God, a sinful man named Isaiah was commissioned to be a prophet of the Lord. In all the subsequent highs and lows of his long prophetic ministry, it was the holiness of God displayed in this vision that kept Isaiah faithful to the Lord.

Verse 3 contains the most direct and comprehensive statement in all of Scripture concerning the holiness of God.

“Holy, holy, holy is the LORD of hosts;
the whole earth is full of his glory!”

Isaiah 6:3

The three-fold affirmation is not only for the sake of emphasis, but also for the sake of affirming the quality of God’s holiness. If Isaiah was English and the seraphim were shouting this out in English, it would read,

“Holy, holier, holiest is the LORD of vast armies;
the whole earth is full of his glory!”

According to verse 4, the building itself shuddered in awe-filled fear at this display of God’s holiness.

And the foundations of the thresholds shook at the voice of him who called, and the house was filled with smoke.

Isaiah 6:4

How does mankind compare to this glorious holiness of God? Verse 5 is, without doubt, one of the most accurate comparisons.

And I said: “Woe is me!
For I am lost;
for I am a man of unclean lips,
and I dwell in the midst of a people of unclean lips;
for my eyes have seen the King, the LORD of hosts!”

Isaiah 6:5

God is holy; we are unclean.

God is not only set apart by being in Heaven, but even in Heaven he is set apart because of His holiness; we on the other hand, are surrounded by other unclean beings just like us.

The angels who dare not stare at God’s holiness remind us that it would be utterly impossible for us to behold God’s holiness. That is why Isaiah realised his cursed state for seeing God’s holiness. The only way for us to appreciate the holiness of God, is if God would mercifully make us holy. This is what He did for Isaiah in verses 6 and 7.

Then one of the seraphim flew to me, having in his hand a burning coal that he had taken with tongs from the altar. And he touched my mouth and said: “Behold, this has touched your lips; your guilt is taken away, and your sin atoned for.”

Isaiah 6:6-7

God’s great mercy does not negate His glorious holiness. We are saved, not when God turns down His holiness, but, when in the presence of His utter holiness, He reaches out and forgives our sin and makes us guiltless.