“I am seeking, I am striving, I am in it with all my heart.”

Source: 2005 GDC Keynote https://www.youtube.com/watch?v=w9HUMt2rrOI

Source: Othello

The Twelfth Revelation, Chapter 26
Context: After this our Lord shewed Himself more glorified, as to my sight, than I saw Him before wherein I was learned that our soul shall never have rest till it cometh to Him, knowing that He is fulness of joy, homely and courteous, blissful and very life.
Our Lord Jesus oftentimes said: I IT AM, I IT AM: I IT AM that is highest, I IT AM that thou lovest, I IT AM that thou enjoyest, I IT AM that thou servest, I IT AM that thou longest for, I IT AM that thou desirest, I IT AM that thou meanest, I IT AM that is all. I IT AM that Holy Church preacheth and teacheth thee, I IT AM that shewed me here to thee. The number of the words passeth my wit and all my understanding and all my powers. And they are the highest, as to my sight: for therein is comprehended — I cannot tell, — but the joy that I saw in the Shewing of them passeth all that heart may wish for and soul may desire. Therefore the words be not declared here; but every man after the grace that God giveth him in understanding and loving, receive them in our Lord’s meaning.

"One And Many"
Find Me (2007)

A Heartbreaking Work Of Staggering Genius (2000)

Inès, describing her path to Hell, Act 1, sc. 5
Source: No Exit (1944)

Quoted in A Few inches of Ivory, 24 November 2013, Jstor Organization http://www.jstor.org/discover/10.2307/23001425?uid=3738256&uid=2129&uid=2&uid=70&uid=4&sid=21102981873241,

Letter to the Soldiers of Coroticus (c.450?)
Context: I am Patrick, yes a sinner and indeed untaught; yet I am established here in Ireland where I profess myself bishop. I am certain in my heart that "all that I am," I have received from God. So I live among barbarous tribes, a stranger and exile for the love of God. He himself testifies that this is so. I never would have wanted these harsh words to spill from my mouth; I am not in the habit of speaking so sharply. Yet now I am driven by the zeal of God, Christ's truth has aroused me. I speak out too for love of my neighbors who are my only sons; for them I gave up my home country, my parents and even pushing my own life to the brink of death. If I have any worth, it is to live my life for God so as to teach these peoples; even though some of them still look down on me.

Stanley J. Kunitz and Howard Haycraft (eds.), Twentieth Century Authors, New York: H.W. Wilson Company, 1942, p. 342.