There was a much the mystical christ than Israel, namely the nations. God declares in Isaiah 49:6 that it was too small a thing for His servant to raise up the tribes of Jacob and restore the preserved of Israel, but He would also make Him a light of the nations so that Gods salvation would go to the end of the earth.
Israel Not forgotten
This does not mean that God had forgotten Israel as verse 14 – 17 reads, “But Zion said, “The Lord has forsaken me, And the Lord has forgotten me.” “Can a woman forget her nursing child, And have no compassion on the son of her womb? Even these may forget, but I will not forget you. “Behold I have inscribed you on the palm of my hands; your walls are continually before me.”
God declared He would redeem Israel through His servant (Isaiah 49:5) who would bring back Jacob to God, in order that Israel might be gathered to God. However, he would not only redeem Israel but the nations. Israel had failed to be a light to the nations as God had commanded them (Genesis 18:17-18, 12:3). They had failed to fulfil their great commission to bless the nations and reveal God’s righteousness (Isaiah 48:18-19).
Christ becomes the centre
Gods servant, namely the messiah became the focal point, the one who would not only redeem Israel but the nations, so that all men whether Jew or gentile would be saved through Messiah (scripture). Not of works so that no man may boast (Ephesians).
Christ fulfills all promises (the gentiles grafted in)
God grafts the gentiles in so that “salvation may reach to the end of the earth” and Israel is therefore enlarged as a result. Christ fulfils the promises given to Abraham that in him that “all the nations of the earth shall be blessed”, his descendants become like the sand and offspring like grain. In Abrahams seed (Genesis 22:18) that is Christ (Galatians 3:16), all the nations of the earth shall be blessed.
Christ redeems Israel
Christ is sent to the house of Israel to redeem her through the cross and a new commission (or previous commission made able by Christ) is given to Israel (disciples, the Israel of God – Galatians 6:16), Abrahams descendants (Galatians 3:29), through Christ (Abrahams seed) to be witnesses to the ends of the earth (Isaiah 49:6, Matthew 28:16-20).
This was also spoken of beforehand by the prophet Isaiah in chapter 43:8-13 where he says that “all the nations have gathered together” (Pentecost). God then declares “you are My witnesses” (Acts 1:8) “and My servant whom I have chosen, in order that you know and believe me, and understand that I am he.” Christ chose the disciples (one new man, the commonwealth of Israel) similarly as God had chosen OT Israel to witness that He is the only true God.