Written for Day 30 of the Supernatural Deserved Better Creative Challenge (prompt: peace).
I like to think that when Jack made the Empty "loud" in 15x18, he destabilized it just long enough for a handful of angels and demons to escape back to Earth, and one of those angels was Gadreel.
And Gadreel, who could never be the angel he'd wanted to be, decides he's had enough of Heavenly affairs and cuts out his grace, choosing instead to live as a human.
It isn't easy. He wears his grace in a vial around his neck, and there are many times in those first few weeks when he almost puts it back, but the thought of failing at yet another endeavor is enough to stay his hand.
Besides, he reasons, he doesn't deserve the comfort it would bring.
He spends many days rooting through trash cans for scraps and many nights shivering on park benches before finally stumbling into a homeless shelter. The food there is simple, and the lodgings are cramped, but it's paradise compared to living on the streets, and Gadreel is so grateful to have a roof over his head that it doesn't even occur to him to complain. He gets to know the other shelter inhabitants, listening without judgment to their stories and the circumstances that brought them there, because God does he know what it's like to live with regrets. His quiet, compassionate demeanor wins him many friends, the first he's had in a very long time; and eventually, he catches the eye of the shelter manager, who gives him a job in the community garden.
And Gadreel takes one look at the withered carrots, struggling cornstalks, and puny tomatoes, the best yield the mediocre inner-city soil has to offer, and he makes a choice: when no one is looking, he takes his grace from the vial and folds it lovingly into the earth.
Within a few weeks, the city paper is publishing a story about the garden's seemingly miraculous turnaround and how it's now producing so much food and at such a high quality that local restaurants are clamoring to buy the surplus. The proceeds, in turn, are invested back into the shelter, which is able to procure more beds and warm clothes and even able to hire part-time counselors to provide therapy for those in need.
As the years go by, Gadreel works his way up to a managerial position within the shelter, although he continues to tend to the garden with care. He becomes a well-known figure in the community, organizing restoration projects at neighborhood parks and bake sales to benefit the local children's hospital, and it's there that he meets and falls in love with a gentle-eyed nurse named, of all things, Eden.
The two marry and build a home together, and it's a modest home, but it's filled with joy and the laughter of children and, eventually, grandchildren. And every time Gadreel sits down with them at the table, he thinks about how Abner had it right, that the key to happiness is getting the one thing you want—in Gadreel's case: family, acceptance, love—and never letting it go. It took him millennia and even dying once to find it, but he has it now, and he's determined to keep it.
Years later, Gadreel’s life finally draws to a close, and he dies peacefully in his sleep, surrounded by family and friends. And he's missed and mourned, but he’s also celebrated and remembered, not for the mistakes he made as an angel but for all the good he did as a man.
And that, in the end, is enough.