In the parable of the
Lost Sheep, the shepherd risks everything to go in search of the lost sheep. To leave the ninety-nine sheep, which would be his entire livelihood, in search of the one lost sheep, would have been ludicrous. It made more sense to write-off the lost sheep, but God is willing to risk everything; sending His beloved Son to offer Himself in sacrifice so that we might have life and have it abundantly.
Once found (faith and repentance), all of Heaven rejoices!