Isaiah 6:1–5 (Isaiah’s vision of the holy Jehovah)
1In the year that king Uzziah died I saw the Lord sitting upon a throne, high and lifted up; and his train filled the temple. 2Above him stood the seraphim: each one had six wings; with twain he covered his face, and with twain he covered his feet, and with twain he did fly.
3And one cried unto another, and said, Holy, holy, holy, is Jehovah of hosts: the whole earth is full of his glory.
4And the foundations of the thresholds shook at the voice of him that cried, and the house was filled with smoke.
5Then said I, Woe is me! for I am undone; because I am a man of unclean lips, and I dwell in the midst of a people of unclean lips: for mine eyes have seen the King, Jehovah of hosts. (American Standard Version, public domain)
The song below takes me back a few years, what great harmonies (made popular by 4Him). As for the main idea here: my mind cannot begin to fathom the holiness of God.