You see, for me that God of the clergy is as dead as a doornail. But does that make me an atheist? Clergymen consider me one — que soit — but you see, I love, and how could I feel love if I were not alive myself or if others were not alive, and if we are alive there is something wondrous about it. Now call that God or human nature or whatever you like, but there is a certain something I cannot define systematically, although it is very much alive and real, and you see, for me that something is God or as good as God. You see, when in due course my time comes, one way or other, to die, well, what will keep me going even then? Won’t it be the thought of love (moral or immoral love, what do I know about it?)

Vincent van Gogh (1853-1890) Dutch painter

Letter to Theo Van Gogh (c. 21-23 Dec 1881) [tr. van Gogh-Bonger]
    (Source)

Alt trans.:

• "That God of the clergymen, He is for me as dead as a doornail. But am I an atheist for all that? The clergymen consider me as such -- be it so; but I love, and how could I feel love if I did not live, and if others did not live, and then, if we live, there is something mysterious in that. Now call that God, or human nature or whatever you like, but there is something which I cannot define systematically, though it is very much alive and very real, and see, that is God, or as good as God. To believe in God for me is to feel that there is a God, not a dead one, or a stuffed one, but a living one, who with irresistible force urges us toward aimer encore [more love]; that is my opinion."
• "Look, I find the clergymen’s God as dead as a doornail. But does that make me an atheist? The clergymen think me one – be that as it may – but look, I love, and how could I feel love if I myself weren't alive and others weren't alive? And if we live, there's something wondrous about it. Call it God or human nature or what you will, but there’s a certain something that I can't define in a system, even though it's very much alive and real, and you see, for me it’s God or just as good as God. Look, if I must die in due course in one way or another, fine, what would there be to keep me alive? Wouldn't it be the thought of love (moral or immoral love, what do I know about it?)." (Source)