Did the Promised Land Protect Israel from Demons?

Why do the Gospels record so little demonic activity in Judea proper? And what do we make of Psalm 91, a psalm with a long history of use as a protective text, even an exorcistic one, whose threats are described with the vocabulary of foreign gods? Was the promised land a sacred space that warded off hostile spirits? And if so, why would Israel need a protective psalm at all?