I have been pondering what it is that I most value in my favourite books of the 'fantasy' genre - or indeed in other media such as movies and TV. And I think it is a particular 'enchanted' feel, which could be described as including both animism and providence.
Animism is the conviction that the natural world is alive and conscious - such that living beings (animals, trees) are also conscious; but most specifically those things that are usually considered to be not-alive ('dead') such as mountains, rivers, the sea - are also considered to be alive, aware, purposive to some significant degree.
Thus, when the protagonists of a high fantasy are on a journey, then the landscape through which they move is a 'character' (or series of characters) in the story.
Whereas in a low fantasy (sword and sorcery etc.) the landscape is just an environment: background scenery, or a series of challenges.
Providence in high fantasy refers to the fact (or sense) that there is someone in the background influencing the course of events; more generally that there is a purpose or destiny (direction or teleology) influencing events.
In high fantasy there is a 'macro' level of meaning, above or behind the plot.
By contrast; low fantasy may be set in the context of a 'micro', close-up reality that is not going anywhere in particular - and success and failure tend to be defined in terms of happiness versus misery, attaining personal goals versus being thwarted or killed.
From a Christian perspective, both animism and providence could be seen as referencing divine creation - a reality of meaning, purpose and personal relatedness; or even as a foretaste of the condition of Heaven.
In this sense, high fantasy is an intrinsically Christian genre - since the personal-divine basis of reality is pretty-much specific to Christianity.
Note added: The original English 'definition' of Romanticism comes from Wordsworth and Coleridge Lyrical Ballads (1798); in relation to which it was said that Wordsworth was writing about (implicitly animistic) nature, and Coleridge was dealing with the supernatural (with reference to some kind of providence).