Isaiah 6:6-7
Then one of the seraphim flew to me, having in his hand a live coal which he had taken with the tongs from the altar. And he touched my mouth with it, and said:
“Behold, this has touched your lips; Your iniquity is taken away, And your sin purged.”

Standing in the holy presence of Almighty God, Isaiah said, “Woe is me! I am undone!”
Rightfully so!
How can the sinful creature stand with head held high in the presence of the Holy Creator?
God sends His seraphim to touch the mouth of Isaiah with a live coal and purge away his sin.
Through His magnificent grace, love, and forgiveness, He is always ready to purge sin.
Once sin is overcome by grace, then you are ready for the service of God.