Existentialism isn't so atheistic that it wears itself out showing that God doesn't exist. Rather, it declares that even if God did exist, that would change nothing.
Love animals: God has given them the rudiments of thought and joy untroubled. Do not trouble their joy, don't harrass them, don't deprive them of their happiness, don't work against God's intent. Man, do not pride yourself on superiority to animals; they are without sin, and you, with your greatness, defile the earth by your appearance on it, and leave the traces of your foulness after you - alas, it is true of almost every one of us!
...to return to their 'native soil,' as they say, to the bosom, so to speak, of their mother earth, like frightened children, yearning to fall asleep on the withered bosom of their decrepit mother, and to sleep there for ever, only to escape the horrors that terrify them.
One's own free unfettered choice, one's own caprice-however wild it may be, one's own fancy worked up at times to frenzy-is that very "most advantageous advantage" which we have overlooked, which comes under no classification and against which all systems and theories are continually being shattered to atoms... [an]will attain his object-that is, convince himself he is a man and not a piano-key!
...a condemned man who, at the hour of death, says or thinks that if the alternative were offered him of existing somewhere, on a height of rock or some narrow elevation, where only his two feet could stand, and round about him the ocean, perpetual gloom, perpetual solitude, perpetual storm, to remain there standing on a yard of surface for a lifetime, a thousand years, eternity! - rather would he live thus than die at once? Only live, live, live! - no matter how, only live!
Remember that you must never sell your soul. Never accept payment in advance.... Never give a work to the printer before it is finished. This is the worst thing you can do.... It constitutes the murder of your own ideas.
Paradise is hidden in each one of use, it is concealed within me too, right now, and if I wish, it will come for me in reality, tomorrow even, and for the rest of my life.