Parable of the Lost Sheep told by Jesus in the Bible.
It means a shepherd leaves a safe group of 99 sheep to search for one lost sheep
Luke 15 & Matthew 18 It tells of a shepherd who leaves his 99 safe sheep in the wilderness to search for the one that has gone astray, illustrating a relentless pursuit of the lost.
John 10:27-28 “my sheep hear my voice. And I know them, and they follow me.”