The Children Of Israel, or for brevity, Israel, is an ethnic group.   

The Children Of The Lord, or for clarity, Christians, is a universal brotherhood that spans race, ethnicity, gender and class.   

Then Peter opened his mouth, and said, Of a truth I perceive that the Lord is no respecter of persons: Act 10:34 To be a respecter of persons implies that one is unjust.     It is impossible for the Lord to be unjust.     He is holy and perfect in all His ways.      The concept of Chosen People is perverse.     Abraham believed the Lord and the Lord rewarded His faith with a promise that His seed would be blessed.     And that one particular seed would bless all the nations of the earth.     That seed is Christ Jesus.      Hebrews are blessed as long as they operate in faith, just as gentiles.

A proper understanding of our Creator (which is only possible through Christ Jesus) reveals the love, mercy and Grace of our Creator and Saviour.   

This understanding precludes anything that is less than just, less than beautiful, less than admirable, less than perfect, in the Lord.   

The Lord created Adam and gave him dominion over all the earth.   Adam was given the calling to subdue the earth and to replenish it.   His failure to submit to the Lord resulted in him being cast out of Eden.   

Noah was commissioned by the Lord to build ark whereby mankind could be replenished after the Flood of judgment.   

Abraham was chosen by the Lord to be the progenitor of the new Adam, Christ Jesus, who would be the Saviour of the world.   

It was always the Lord's plan for all men to be His children.   

For the Holy Spirit so loved the world, that he gave his only begotten Son, that whoever believes in him should not perish, but have everlasting life. Joh 3:16 The Holy Spirit is the eternal, omniscient, omnipresent, omnipotent Creator of all things by the Word.      What world is John speaking of?      The earth and all the people born into humanity.      The Holy Spirit is love and love is of the Holy Spirit.      The world was created by our Lord and it is good.     We know that man chose rebellion against the Holy Spirit and so humanity became evil.     But the Holy Spirit loves the people of this world and so He birthed Christ Jesus into the world to redeem it and us.      The Gospel is heard and those who are hungry are lead by the Holy Spirit to believe and receive the Truth.      The Truth sets us free from sin, from death and hell and brings us to Eternal Life by the infilling of the Holy Spirit.      Here is understanding:    → Everlasting Life is Eternal Life    → Eternal Life is union with the Holy Spirit.

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. 2Pe 3:9 The Lord is love and His love is manifest in Christ who made it possible for us to be born of His Holy Spirit and so be In Christ.      But, He gives us the choice between life and death.     When a person receives Christ Jesus they receive Eternal Life.     When a person rejects Christ Jesus they enter into Eternal Death against the Lord's will.      This verse totally undermines the false doctrine of Extreme Sovereignty.     We do not see all men coming to repentance so the Lord's will is not done with respect to every human being.

The Lord uses people to accomplish His purposes in the earth.   Those who are called are instruments of the Word and Holy Spirit.   That is all.   

Abraham was receptive to the call of the Lord proving his faith by leaving his family and going to the land of promise.   This is to his honor.   

Even as Abraham believed the Lord, and it was accounted to him for righteousness. Gal 3:6 Abraham being the first benefactor of Grace by faith

Abraham's seed of promise is Christ Jesus.   It is patently obvious that most of Abraham's descendants were not seeds of promise.   

Because all those men which have seen my glory, and my miracles, which I did in Egypt and in the wilderness, and have tempted me now these ten times, and have not hearkened to my voice; Num 14:22

Does the Lord save nations or ethnic groups?   
Does the Lord destroy nations or ethnic groups?   
Yes to both questions.   But, the saving and destroying have to do with the strength of His Laws.   

Nations which observe His laws are saved while nations which forget Him and His laws are destroyed.   

Blessed is the nation whose god is the Lord; and the people whom he has chosen for his own inheritance. Psm 33:12 Alignment with the Lord is good.      Rebellion against the Lord is suicide.

The wicked shall be turned into hell, and all the nations that forget the Lord. Psm 9:17 This is the law of the Lord and it is immutable.      Understand that hell is a destination of destruction, misery and death.     This verse is telling us that every nation that forgets the Lord will fall into destruction, misery and cease to exist.      Hell will be cast into the Lake Of Fire at The Judgment.     Rev 20:14

But spiritual salvation ( Eternal Life) can only happen to an individual person.   We are not Born Again in groups, but one at a time, according to our Faith in Christ Jesus.   

Does the nation of Israel have a spirit?   No.   It does have a corporate consciousness and will which affects their future for good or evil.   

But spiritual Israel, the Body Of Christ, does have a Spirit and He is the Holy Spirit which produced the Saviour, Jesus Christ who is King Of Kings and Lord Of Lords.   

In summary,
   → There is no replacement of the Children Of Israel as the Children Of The Lord because
   → the Children Of Israel have never been anything more than the children of Israel.   
   → Abraham's calling was fulfilled in one thread, not in every person of every generation.   
   → There never has been and never will be a physically, genetically defined Chosen People.   
   → The Chosen People are those In Christ Jesus who have not only been called but chosen by having faith in Him as Mighty God, Everlasting Father, Saviour and Lord.   

That which is born of the flesh is flesh; and that which is born of the Holy Spirit is spirit. Joh 3:6 Our spirit and our flesh exist in different realms.      Our Spirit exists in the Spirit Realm while our body exists in the Physical Realm.      Our Lord is Spirit Joh 4:24 (the Holy Spirit) and, as such, His existence is in the Spirit Realm.     That is why we must be born of the Spirit Joh 3:7 - so we can be one with the Holy Spirit Joh 17:21.      But the Holy Spirit also exists in the Physical Realm in Christ Jesus Joh 3:13.      As the Holy Spirit breathed life into Adam, so He did into the womb of Mary Mat 1:18, and Jesus, the eternal, Incarnate Word Joh 1:1 became a living human soul Joh 1:14.      Our Lord Jesus is Spirit Soul And Body 1Th 5:23 just as are we who were created in His image Gen 1:26.