a-gift-from-god
Explanation
The Joke
A nun is teaching a group of children the uplifting religious saying, "Remember kids, every day is a gift from God!" This is a common inspirational phrase meant to encourage gratitude for being alive, treating each new day as a precious present.
The second panel subverts this by showing God in the clouds with a wrapped gift box, commenting: "Ha! It looks nice, but when you open the top, it's a worldwide pandemic." God is essentially admitting that while the "gift" of each day may look pleasant on the outside, the actual contents are terrible -- specifically, a worldwide pandemic.
The Humor
The comedy comes from taking the metaphor "every day is a gift" completely literally and then revealing that God is a terrible gift-giver. Instead of the phrase being a comforting platitude about gratitude, it becomes a darkly funny admission that life is actually full of suffering disguised in attractive packaging. The image of God as a prankster who wraps catastrophes in pretty gift boxes is a classic SMBC move -- taking a well-known religious or philosophical concept and following it to an absurd, uncomfortable logical conclusion. Published on December 30, 2016, this comic also has a somewhat prescient quality given the COVID-19 pandemic that would arrive a few years later.