John Newton:

I am not what I ought to be. Ah, how imperfect and deficient!

I am not what I wish to be. I abhor what is evil, and I would cleave to what is good!

I am not what I hope to be. Soon, soon shall I put off mortality, and with mortality all sin and imperfection.

Yet, though I am not what I ought to be,
nor what I wish to be,
nor what I hope to be,
I can truly say, I am not what I once was;
a slave to sin and Satan;
and I can heartily join with the apostle, and acknowledge,
‘By the grace of God I am what I am.’

And check out this excellent church video made by the folks at Grace Community Church in San Antonio, Texas:

HT: T-Wax