The Parable of the Lost Coin:
Luke 15:8-10

“Or suppose a woman has ten silver coins and loses one. Does she not light a lamp, sweep the house and search carefully until she finds it? And when she finds it, she calls her friends and neighbors together and says, ‘Rejoice with me; I have found my lost coin.’ In the same way, I tell you, there is rejoicing in the presence of the angels of God over one sinner who repents.”