Godsend

(n.) Something sent by God; an unexpected acquisition or piece of good fortune.

Thesaurus Entries

advantage, benediction, benefit, blessing, boast, bonanza, boon, catch, diamond, find, gem, gift, good thing, jewel, loaves and fishes, manna, manna from heaven, pearl, plum, pride, pride and joy, prize, treasure, trophy, trouvaille, windfall, winner