Holiness is a moral attribute of God. At its core, holiness means to be distinct, set apart. The biblical word “holy” (as it applies to God) carries with it the idea of God being separate and distinct from any other person or anything else in the entirety of the universe. Holiness also imparts the fact that God (being uncreated and eternal) “does not depend on anyone or anything to bring Him into existence or to sustain Him in being.” 
God’s holiness means He is majestic and powerful. The Scriptures declare “There is no one holy like the LORD, Indeed, there is no one besides You, nor is there any rock like our God. (1 Samuel 2:2) God is above and beyond all His creation. He is sovereign over all creation.
Isaiah’s vision of God holiness was breathtaking and awesome. Around the throne of God, the angels cry out “Holy, Holy, Holy is the Lord of hosts, the whole earth is full of His glory.” (Isaiah 6:3). Nothing can compare to the God of Scripture.
In Revelation 4, John gives us a companion scene to Isaiah’s vision. The cries of “Holy, Holy, Holy” rise up continually amidst the throne of God. He is awesome, mighty, and powerful. No one can resist His plans.
Dear fellow Believer, the God of the Bible is holy. The God we serve and owe everything to, He is Holy, Holy, Holy. He calls us to be holy and separate as well. “Come out from among them and be separate, says the Lord.” (2 Corinthians 6:7) He is holy. Therefore, we should seek holiness every day.
 Feinberg, John S., No One Like Him, pg. 340