The LORD reigneth; let the people tremble: He sitteth between the cherubims; let the earth be moved.
The LORD is great in Zion; and He is high above all the people.  Let them praise Thy great and terrible name; for it is holy.  The king’s strength also loveth judgment; Thou dost establish equity, Thou executest judgment and righteousness in Jacob.
Exalt ye the LORD our God, and worship at His footstool; for He is holy.  Moses and Aaron among His priests, and Samuel among them that call upon His name; they called upon the LORD, and He answered them.  He spake unto them in the cloudy pillar: they kept His testimonies, and the ordinance that He gave them.  Thou answeredst them, O LORD our God: Thou wast a God that forgavest them, though Thou tookest vengeance of their inventions.
Exalt the LORD our God, and worship at His holy hill; for the LORD our God is holy.

Psalm 99:1-9

It could also be said, “Because our LORD is holy, He is great.”

The LORD God who is holy is worthy of our praise and worship.  Why because He is holy.  There is no god; but the LORD He is the only God.  That is why He is holy, and because there is no wickedness, evil, neither uncleanness in Him.

The LORD God even tells His people, “Be holy; for I am holy” (Leviticus 11:44-45; 1 Peter 1:16).

How can we be holy?  First of all we must realize that we are unholy, and separated from holy God.  The only way we can be  holy is through Jesus Christ, God’s holy and only begotten Son, and believing in Him, confessing Him as Lord, and believing that God raised Him up from the grave alive forever more.

“You be holy, for I am Holy,” saith the LORD.