For thus says the Lord Yahweh: "Behold, I myself, even I, will search for my sheep, and will seek them out." — Ezekiel 34:11
I am the good shepherd. The good shepherd lays down his life for the sheep. — John 10:11

Author
Charles Spurgeon
Summary: Jesus seeks and saves those the Father has given him, even while they are still wandering and do not know the shepherd. So we can have hope and pray for those who are dear to us: just as he found us, he will find them too. If someone from his flock turns away from truth and holiness, even falling into error, sin, or despair, the Lord will pursue them through his providence and grace. He will not allow any of them to perish. When we recognize ourselves as lost sheep, we can hold fast to this promise and cry out to him.
This He does at the beginning, when His chosen ones are like stray sheep that know neither the shepherd nor the flock. How wonderfully the Lord finds His chosen ones! Jesus is magnificent both as a shepherd who tracks them down and as a shepherd who saves them.
Though many of those whom His Father gave Him had come as close to the gates of hell as they possibly could, still the Lord, after searching and searching, discovers them and draws near to them in grace. He has found us: let us have good hope for those laid on our hearts to pray for, for He will find them too.
The Lord repeats this process whenever any member of His flock strays from the pastures of truth and holiness. They may fall into grave error, grievous sin, and dreadful hardness of heart; yet the Lord, who has become their surety before His Father, will not allow any of them to go so far as to perish. By His providence and His grace, He will follow them into strange lands, into dwellings of poverty, into caves of darkness, into the depths of despair; He will lose none of those whom His Father has given Him. For Jesus, seeking and saving the whole flock, without a single exception, is a matter of honor. What a promise I have to plead if, at this hour, I am compelled to cry, “I have gone astray like a lost sheep”!
Source: The Cheque Book of the Bank of Faith. Translation by Allan Roman.
http://www.spurgeon.com.mx/chequera/meditames/abril.pdf