Upon the sandy shore an empty shell,
Beyond the shell infinity of sea;
O Saviour, I am like that empty shell;
Thou art the Sea to me.

A sweeping wave rides up the shore, and, lo,
Each dim recess the coiled shell within
Is searched, is filled, is filled to overflow
By water crystalline.

Not to the shell is any glory then:
All glory give we to the glorious sea.
And not to me is any glory when
Thou overflowest me.

Sweep over me, Thy shell, as low I lie,
I yield me to the purposes of Thy will;
Sweep up, O conquering waves, and purify.
And with Thy fulness fill.

Amy Carmichael, 1867 – 1951

For more insight into this poem: What have I got in my pocket?