Glory, Holiness and the Sacred Earth
Peter Leithart recently offered this robust definition of 'holy' on his blog: "Holy in Scripture means 'claimed by indwelling glory.'" He also offered these examples: "The tabernacle is consecrated as holy space by the indwelling glory of Yahweh. Saints are those claimed by the indwelling of the Spirit."
But using his definition (which I think is reasonable) brings even more life to the familiar Isaiah 6:3 and implies the basis for our hope of Christ becoming all in all.
And one cried unto another, and said, "Holy, holy, holy, is the LORD of hosts: the whole earth is full of his glory."
The mystery of our faith is this, that the creator God, YHWH, the LORD of hosts, rather than remaining aloof from his creation, has himself always been and always will be the sanctifier of the cosmos.