Augustus Toplady wrote this hymn text in an effort to demonstrate that man's own efforts could never satisfy the eternal justice of a holy God. He originally entitled the hymn "A Living and Dying Prayer for the Holiest Believer in the World".
There was apparently an argument between Toplady and the Wesleys, John and Charles, regarding the "work" of man or the work of God in salvation. Ironically, some of Toplady's verses seemed to have come from a text earlier written by Charles Wesley, "O Rock of Israel, Rock of Salvation, Rock struck for me, let those two streams of Blood and Water which once gushed out of Thy side, bring down Pardon and Holiness into my soul. And let me thirst after them now, as if I stood upon the Mountain whence sprang this Water; and near the Cleft of that Rock, the Wounds of my Lord, whence gushed this Sacred Blood."
Rock of Ages
Rock of ages, cleft for me,
Let me hide myself in Thee;
Let the water and the blood,
From Thy wounded side which flowed,
Be of sin the double cure,
Save from wrath and make me pure.
Could my tears forever flow,
Could my zeal no languor know,
These for sin could not atone--
Thou must save, and Thou alone;
In my hand no price I bring,
Simply to Thy cross I cling.
While I draw this fleeting breath,
When my eyes shall close in death,
When I rise to worlds unknown
And behold Thee on Thy throne,
Rock of Ages, cleft for me,
Let me hide myself in Thee.
Jesus Christ is the only Rock upon which to found truth, upon which to base faith, and upon which to live.
(Information for this post taken from 101 Hymn Stories by Kenneth W. Osbeck, Kregel Publications, 1982)