a-reason
Explanation
The Joke
The comic shows God being confronted by a man who demands to know: "God, does everything happen for a reason?" God confirms, "Yes, me." He then proceeds to give deeply unsatisfying "reasons" for terrible things. When asked why grandma died young, God explains it was because in 1955 he "brainwashed" her hated uncle so that a specific sequence of events involving a sink, which could have been repaired, led to her death. When asked "And how my son hates me?" God explains it was due to a single synapse firing caused by a stray ion hitting the brain at a specific moment they were both conscious.
The man then asks about his parents'' car wreck, and God says it was "faulty wiring because a factory worker got his hand stuck in a pool filter at the worst possible moment." The man protests: "You can''t just put a pool of life in the joke while holding it!" to which God responds, "You know, you could fix this whole system." Someone off-panel says, "Amigo, hey! Who told you this was no bueno?" The comic ends with a note that it was a promotional strip for "Soonish" (click for more info).
The Humor
The comic takes the comforting religious notion that "everything happens for a reason" and twists it into absurdity by having God confirm that yes, there are reasons -- but they are all meaningless chains of arbitrary causation rather than part of any grand plan. Grandma did not die for a higher purpose; she died because of a cascade of trivial coincidences involving a broken sink and a vindictive uncle. The humor lies in the gap between what people mean when they say "everything happens for a reason" (implying purpose and meaning) and the literal truth that everything does have a cause -- just not a meaningful one. God is technically telling the truth while completely undermining the comforting intent of the phrase.
References
This is one of the promotional comics for "Soonish: Ten Emerging Technologies That''ll Improve and/or Ruin Everything" by Zach and Kelly Weinersmith. The comic plays with the philosophical distinction between teleological explanations (things happen for a purpose) and mechanistic explanations (things happen due to prior causes). This distinction is central to debates in philosophy of science and theology about whether the universe has inherent purpose or is merely a chain of cause and effect.