“The longing for Paradise is man's longing not to be man.”

Source: Epistulae Morales ad Lucilium (Moral Letters to Lucilius), Letter LXX: On the proper time to slip the cable, Line 4.

Thoughts on Various Subjects from Miscellanies (1711-1726)
Variant: All would live long, but none would be old.
Source: Gulliver's Travels

Es irrt der Mensch, so lang er strebt.
Variant translation: Man will err while yet he strives.
Prologue in Heaven
Faust, Part 1 (1808)

An Atheist Manifesto

Freedom and Death (1956)
Context: God, what is all this talk put out by the popes? Paradise is here, my good man. God, give me no other paradise!

The Secret of Letting Go

Epistulae ad Atticum (Letters to Atticus) Book IX, Letter X, section 3
Often paraphrased as: Dum anima est, spes est ("While there is life there is hope")
Compare: "While there's life there’s hope, and only the dead have none." Theocritus, Idyll 4, line 42; as translated A. S. F. Gow

Source: Night-Thoughts (1742–1745), Night IV, Line 118.