When we say that God is holy we do not simply mean that He does not sin. That is true, of course. God’s holiness has an ethical dimension. The Bible says that “the holy God will show Himself holy by His righteousness” (Isa. 5:16b). God is undefiled in all His ways. He is the supreme, the superlative moral majesty in the universe. But God’s holiness refers to more than His ethics. Holiness refers to everything that distinguishes the Creator from His creation. It is the infinite distance between His deity and our humanity. Holiness is the very “Godness” of God, the sum total of all His glorious perfections.
Philip Graham Ryken