Matthew 18:12-14
Jesus said to his disciples:
“What is your opinion?
If a man has a hundred sheep and one of them goes astray,
will he not leave the ninety-nine in the hills
and go in search of the stray?
And if he finds it, amen, I say to you, he rejoices more over it
than over the ninety-nine that did not stray.
In just the same way, it is not the will of your heavenly Father
that one of these little ones be lost.”
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It's important to remember that Christ's ultimate mission on Earth was to save US. He came to save the world collectively, but he also came to save each one of us individually. He has a personal knowledge of and caring for each one of us. Jesus, the most powerful person in the history of the earth, came for each one of specifically. This is something that we all know and were taught from a young age, but it's another one of those things that ultimately we can't truly understand. Until, God willing, we get to meet Him, and it all becomes clear.
Here's what the Catechism says about this passage:
605 At the end of the parable of the lost sheep Jesus recalled that God's love excludes no one: "So it is not the will of your Father who is in heaven that one of these little ones should perish." (410) He affirms that he came "to give his life as a ransom for many"; this last term is not restrictive, but contrasts the whole of humanity with the unique person of the redeemer who hands himself over to save us. (411) The Church, following the apostles, teaches that Christ died for all men without exception: "There is not, never has been, and never will be a single human being for whom Christ did not suffer."(412 )
(Catechism footnotes)
410. Mt 18:14.
411. Mt 20:28; cf. Rom 5:18-19.
412. Council of Quiercy (853): DS 624; cf. 2 Cor 5:15; 1 Jn 2:2.
