Jesus tells of a shepherd who has 100 sheep but leaves the 99 to search for the one that is lost. When he finds it, he rejoices more over that one than over the 99 who never went astray.
God values every person and actively seeks those who are lost. It is not His will that anyone should perish, especially the "little ones" or the spiritually vulnerable. This parable highlights God's compassion and pursuit of the lost.