Where is my soul's true rest?

TEXT:
"Not what I am, O Lord, but what Thou art,
That, that alone can be my soul's true rest.
Thy love not mine bids all fear and doubt depart,
And stills the tumult of my troubled breast.

Girt with the love of God on every side,
I breathe that love as heaven's own healing air;
I work and pray, and follow still my guide,
And fear no foe, escaping every snare.

'Tis what I know of Thee, my Lord and God,
That fills my soul with peace, my lips with song;
Thou art my health, my joy, my staff, my rod;
I lean on Thee, in weakness I am strong." - Horatius Bonar

DISCUSSION:

Why might the text be true - the Science of it?

Share any experience of it.

Where is my soul's true rest?