sign
Explanation
A man stands on a hillside praying, asking God for a sign to restore his wavering faith: "Lord, I'm losing my faith. If you're real, if you're out there, please... give me a sign." In the next panel, a giant sign appears in the sky reading "I DON'T EXIST."
The man responds, "That was mean, God," and the final panel shows God in heaven laughing hysterically ("AHAHAHAHA...") while an angel looks on.
The joke works on multiple levels. First, there is the logical paradox: if God sends a sign saying He does not exist, the very act of sending the sign proves He does exist, making the sign's message a deliberate lie. Second, it portrays God as a prankster who finds it hilarious to torment a sincere believer with a cruel joke. Third, it plays on the philosophical tension between faith and evidence -- the man asked for evidence, and the evidence he received is maximally unhelpful. The comic is a characteristic Weinersmith take on theology, treating God as an entity who exists but enjoys messing with people rather than providing comfort.