Literally, it should be a Protestant missionary way. The front is looking for a lost lamb, because in Christianity, everyone is a lamb, and the Lord Jesus is a shepherd. The back means May the Lord be with you. Hehe, it's not a mystery, it's just that the parishioners are teaching in another way.
Now some lawless people use this sentence to fish, and most of them stick it near the girls' dormitory to lure virtuous girls, so be careful to be deceived.