The best modern hymns - though he, for good reasons, prefers to call them "carols" - I would say, are those made by Sydney Carter. And the interesting thing about many of them are that they take a very agnostic stance.You can read them several ways, and sing them from a range of different views about the world we live in.

For example you have Friday Morning, where the song is in the voice of one of the thieves crucified alongside Jesus:

It was on a Friday morning
they took me from the cell,
and I saw they had a carpenter
to crucify as well.
You can blame it on to Pilate,
you can blame it on the Jews,
you can blame it on the Devil,
it's God I accuse.
It's God they ought to crucify
instead if you and me
I said to the carpenter
a-hanging on the tree.

Or George Fox, for that matter:

With a book and a steeple
with a bell and a key
they would bind it forever
but they can't, said he.
For the book it will perish
and the steeple will fall
but the light will be shining
at the end of it all.
Old leather breeches, shaggy shaggy locks,
Old leather breeches, shaggy shaggy locks,
with your Old leather breeches,
and your shaggy shaggy locks
you are pulling down
the pillars of the world, George Fox.