For the Son of man is come to seek and to save that which was lost – Luke 19:10

Who are the lost? That would be everyone. Still, even though Jesus died for the world and came to save the world (that which is lost), it does not mean that he promises to save everyone unconditionally. Jesus did his part by dying for the world (making everyone savable, and making the animal sacrifice system obsolete) but we must do our part if we want to use the key he has provided us to his Kingdom. We must believe, repent and endure to the end. Without Jesus Christ our Messiah, we would not be saved no matter what we did because he is the rock and our corner-stone. 

The atonement is likened to a shepherd and his sheep. It is quite possible that a shepherd might lose a sheep, and if that is the case he will naturally go out and look for it. It is not always the case that he will find it (dead or alive), but IF he does, there is much rejoice. A LOST sheep has been FOUND again! A sheep can obviously go from being alive, to being lost to being found again, and that is also the same route that the prodigal son took.

Matt. 18:11 For the Son of man is come to save that which was lost.12 How think ye? if a man have an hundred sheep, and one of them be gone astray, doth he not leave the ninety and nine, and goeth into the mountains, and seeketh that which is gone astray?13 And IF so be that he find it, verily I say unto you, he rejoiceth more of that sheep, than of the ninety and nine which went not astray.

Luke 15:18 I will arise and go to my father, and will say unto him, Father, I have sinned against heaven, and before thee, —  24 For this my son was DEAD, and is ALIVE AGAIN; he WAS LOST, and is FOUND. And they began to be merry. — 32 It was meet that we should make merry, and be glad: for this thy brother was dead, and is alive again; and was lost, and is found.

This is the reason why there is much joy in heaven over each sinner that repents, because this means that someone has gone from death to life! God does not want anyone to perish.

Luke 15:10 Likewise, I say unto you, there is joy in the presence of the angels of God over one sinner that repenteth.

2 Pet. 3:9 The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance.

Ez. 18:³² For I have no pleasure in the death of him that dieth, saith the Lord God: wherefore turn yourselves, and live ye.

Jesus came to save the world rather than judging the world (John 12:47) but in a way people will judge themselves unworthy if they reject their Savior. God does not take pleasure in the death of the wicked.

John speaks below about the mission of Jesus. He was not just the light of certain chosen “elect”, but “the light of men”. John the Baptist started to witness of the Light (Jesus) that ALL MEN through him might believe (not “all sorts of men”). Jesus “lighteth every man that cometh into the world”. It could not be more clear. EVERYONE can be saved through our Messiah, Jesus Christ. So why are not all saved? We read why when we read further about the condition: “as many as received him, to them gave he power to become the sons of God, even to them that believe on his name”. Here we have it. Those who receive him and believe in him (and if we love him, we obey him ….) will become the sons of God. This means that those who do not take this path will not be saved. We can even read that Jesus came to “his own”, but that his own did not receive him. This is likely a reference to the Jews. 

John 1:1 In the beginning was the Word, and the Word was with God, and the Word was God.2 The same was in the beginning with God.3 All things were made by him; and without him was not any thing made that was made.4 In him was life; and the life was the light of men. 5 And the light shineth in darkness; and the darkness comprehended it not.6 There was a man sent from God, whose name was John.7 The same came for a witness, to bear witness of the Light, that all men through him might believe.8 He was not that Light, but was sent to bear witness of that Light.9 That was the true Light, which lighteth every man that cometh into the world.10 He was in the world, and the world was made by him, and the world knew him not.11 He came unto his own, and his own received him not.12 But as many as received him, to them gave he power to become the sons of God, even to them that believe on his name

Who are heavy laden? Only certain chosen elect? Not at all. All who are heavy laden can come to Jesus, and their background does not matter because true repentance takes care of their sinful history. Jesus does not say that he will take the responsibility to place his easy yoke on people by force, but he urges people to “take my yoke upon you, and learn of me” . This is our responsibility:

Matt. 11:28 Come unto me, all ye that labour and are heavy laden, and I will give you rest.29 Take my yoke upon you, and learn of me; for I am meek and lowly in heart: and ye shall find rest unto your souls.30 For my yoke is easy, and my burden is light.

Believers are the salt of the earth, but against God’s will salt can lose its savor. If this happens, when we have lost all interest in learning from Jesus, then we are good for nothing and are cast out. Naturally therefore Jesus urges us to not lose the salt but to endure to the end. Again, God does not want anyone to perish!

Matt 5:13 Ye are the salt of the earth: but if the salt have lost his savour, wherewith shall it be salted? it is thenceforth good for nothing, but to be cast out, and to be trodden under foot of men.

Matt. 10:22 And ye shall be hated of all men for my name’s sake: but he that endureth to the end shall be saved.

We are created to seek the Lord, even though he is not far away from any of us.

Acts 17:26 And hath made of one blood all nations of men for to dwell on all the face of the earth, and hath determined the times before appointed, and the bounds of their habitation;27 That they should seek the Lord, if haply they might feel after him, and find him, though he be not far from every one of us:— 30 And the times of this ignorance God winked at; but now commandeth all men every where to repent:31 Because he hath appointed a day, in the which he will judge the world in righteousness by that man whom he hath ordained; whereof he hath given assurance unto all men, in that he hath raised him from the dead.

Jer. 29:13 And ye shall seek me, and find me, when ye shall search for me with all your heart.

Sometimes in the Bible, we can read about “the lost” when it comes to Israel and/or the Jews (or the house of Israel) as in Matt. 10:6, and Matt. 15:24 but this is another, but similar context of being lost. Similarly the Jews could/can be considered lost when they reject Jesus Christ as the Messiah. Israel has a major part of the Old Testament, and Jesus was born as a Jew to live in the world among Jews.

You can read this article about Jesus dying for the world.