The psalmist is teaching us something simple but important in this Psalm.
God should be worshiped because He is holy. He is pure and higher and
greater than us. Three times in Psalm 99 we are told that God is holy and
the right response is to worship Him!

Majestic Holiness

Moral Holiness

Psalm 99:1-3 The Lord Is Holy In His Reign

Psalm 99:4-5 The Lord Is Holy In His Justice

Psalm 99:6-9 The Lord Is Holy In His Relationships

Read Ahead: Psalm 103