"Seraphim were stationed above;
each of them had six wings:
with two they veiled their faces,
with two they veiled their feet,
and with two they hovered aloft.
"Holy, holy, holy is the LORD of hosts!" they cried one to the other.
"All the earth is filled with his glory!"
(Is 6:2-3)

As our hand shields our eyes from the brightness of the sun, so angels cover their faces in the presence of God's Holiness. So great is God Holiness that no creature can withstand its unveiled presence.

The Holiness of God is the wholeness of his perfection. It is the most fundamental attribute of God and His very essence. It is His Holiness which brings to perfection to all His other attributes such as power, love, goodness, justice, mercy, etc. For example, God's power without holiness would be tyranny, oppression and cruelty; it is God's holiness which makes his justice devoid of passion and caprice. "Divine love does not overlook sin; it pays its consequences, and it must, because it is a holy kind of love, not merely sentimental or affectionate."(Webpage:The Holiness of God by Paul Mizzi)

God reveals his holiness in creation as "glory", but with the fall of man he has chosen to reveal his holiness in His Name.

At the Burning Bush Moses encounters the holiness of God. As he approached the Bush he was told to remove his sandals because he was standing on holy ground. In this manifestation God also reveals his Holy Name (Yahweh or "I Am") The second commandment states, "Keep holy the LORD'S NAME" , and in the Psalms we sing,

"I will extol you, my God and king;
I will bless your name forever.
Every day I will bless you;

I will praise your name forever.
Great is the LORD and worthy of high praise;

God's grandeur is beyond understanding."

(Ps145:1-3)

In the Our Father we are told by Christ to honor as Holy his Father's Name. And it is God's will that his Son, Jesus Christ be honored as we read in Philippians, "Every tongue confess that Jesus Christ is Lord, to the glory of God the Father." And in doing so we honor the Father.

Holy God We Praise Thy Name

Holy God, we praise thy name;
Lord of all, we bow before Thee.
All on earth thy scepter claim,
All in heav'n above adore Thee.
Infinite, thy vast domain,
Everlasting is thy reign.

Thy Kingdom Come