Agnus Dei. C14th stained glass, The Old Library, Merton College, Oxford.

"The next day John again was standing with two of his disciples, and as he watched Jesus walk by, he exclaimed, 'Look, here is the Lamb of God!' " (John 1.35-36).

Samuel Barber, Agnus Dei, op. 11, 1967. Vlaams Radio Choir, dir. Marcus Creed, Brussels, 2015.

Agnus Dei
—Denise Levertov

Given that lambs
are infant sheep,
that sheep are afraid and foolish, and lack
the means of self-protection, having
neither rage nor claws,
venom nor cunning,
what then
is this 'Lamb of God'?

This pretty creature, vigorous
to nuzzle at milky dugs,
woolbearer, bleater,
leaper in air for delight of being, who finds in astonishment
four legs to land on, the grass
all it knows of the world?
With whom we would like to play,
whom we'd lead with ribbons, but may not bring
into our houses because
it would spoil the floor with its droppings?

What terror lies concealed
in strangest words, O lamb
of God that taketh away
the Sins of the World: an innocence
smelling of ignorance,
born in bloody snowdrifts,
licked by forebearing
dogs more intelligent than its entire flock put together?

God then,
encompassing all things, is
defenceless? Omnipotence
has been tossed away,
reduced to a wisp of damp wool?

And we
frightened, bored, wanting
only to sleep 'til catastrophe
has raged, clashed, seethed and gone by without us,
wanting then
to awaken in quietude without remembrance of agony,

we who in shamefaced private hope
had looked to be plucked from fire and given
a bliss we deserved for having imagined it,

is it implied that we
must protect this perversely weak
animal, whose muzzle’s nudgings

suppose there is milk to be found in us?
Must hold in our icy hearts
a shivering God?

So be it.
Come, rag of pungent
quiverings,
dim star.
Let's try
if something human still
can shield you,
spark
of remote light.

Prayer

You are our eternal salvation,
   the unfailing light of the world.
Light everlasting,
   you are truly our redemption.
Grieving that the human race was perishing
   through the tempter's power,
   without leaving the heights
   you came to the depths in your loving kindness.
Readily taking our humanity by Your gracious will,
   you saved all earthly creatures, long since lost,
   restoring joy to the world.
Redeem our souls and bodies, O Christ,
   and so possess us as your shining dwellings.
By your first coming, make us righteous;
   at your second coming, set us free:
   so that, when the world is filled with light
   and you judge all things,
   we may be clad in spotless robes
   and follow in your steps, O King,
   into the heavenly hall.
—Unknown Author, 10th century.