"Suppose one of you has a hundred sheep and loses one of them. Does he not leave the ninety-nine in the open country and go after the lost sheep until he finds it? And when he finds it, he joyfully puts it on his shoulders and goes home. Then he calls his friends and neighbors together and says, 'Rejoice with me; I have found my lost sheep.' I tell you that in the same way there will be more rejoicing in heaven over one sinner who repents than over ninety-nine righteous persons who do not need to repent." Luke 15:4-7
I have seen myself forget the lost sheep over and over again. Same goes for the lost coin and son spoken of later in that chapter.
"But when the Son of Man comes in His glory, and all the angels with Him, then He will sit on His glorious throne. All the nations will be gathered before Him; and He will separate them from one another, as the shepherd separates the sheep from the goats ; and He will put the sheep on His right, and the goats on the left.
Then the King will say to those on His right, 'Come, you who are blessed of My Father, inherit the kingdom prepared for you from the foundation of the world. 'For I was hungry, and you gave Me something to eat ; I was thirsty, and you gave Me something to drink ; I was a stranger, and you invited Me in; naked, and you clothed Me; I was sick, and you visited Me; I was in prison, and you came to Me.'
Then the righteous will answer, when did we see You hungry, and feed You, or thirsty, and give You something to drink ? 'And when did we see You a stranger, and invite You in, or naked, and clothe You?' 'When did we see You sick, or in prison, and come to You?' "The King will answer and say to them, 'Truly I say to you, to the extent that you did it to one of these brothers of Mine, even the least of them, you did it to Me.'
Then He will also say to those on His left, 'Depart from Me, accursed ones, into the eternal fire which has been prepared for the devil and his angels ; for I was hungry, and you gave Me nothing to eat ; I was thirsty, and you gave Me nothing to drink ; I was a stranger, and you did not invite Me in; naked, and you did not clothe Me; sick, and in prison, and you did not visit Me.' Then they themselves also will answer, 'Lord, when did we see, or thirsty, or a stranger, or naked, or sick, or in prison, and did not take care of You?' Then He will answer them, 'Truly I say to you, to the extent that you did not do it to one of these, you did not do it to Me.' These will go away into eternal punishment, but the righteous into eternal life." Matthew 25:31-46
So helping "the least of these" or going to find "the lost sheep" = helping Jesus
and helping Jesus = the Kingdom of Heaven.
"The kingdom of heaven is like a treasure hidden in the field, which a man found and hid again; and from joy over it he goes and sells all that he has and buys that field.
Again, the kingdom of heaven is like a merchant seeking fine pearls, and upon finding one pearl of great value, he went and sold all that he had and bought it.
Again, the kingdom of heaven is like a dragnet cast into the sea, and gathering fish of every kind ; and when it was filled, they drew it up on the beach ; and they sat down and gathered the good fish into containers, but the bad they threw away. So it will be at the end of the age ; the angels will come forth and take out the wicked from among the righteous, and will throw them into the furnace of fire ; in that place there will be weeping and gnashing of teeth." Matthew 13:44-50
So giving your all to help/find "the least of these"/"lost sheep" appears to be the same as giving your all for the hidden treasure or costly pearl scenario! Jesus even once again ends with explaining how God is going to separate the wicked from the righteous at the end of the age.
I turn my back on a lost sheep, when instead Jesus calls me to turn my back on everything else to help a lost sheep! Where is my passion? Where is my heart? I seek perfect alignment with You, Jesus!
O I have been dilatory and dumb;
I should have made my way straight to you long ago;
I should have blabb'd nothing but you, I should have chanted nothing
I will leave all, and come and make the hymns of you;
None have understood you, but I understand you;
None have done justice to you--you have not done justice to yourself;
None but have found you imperfect--I only find no imperfection in
~ Walt Whitman