Within the physical nation of Israel are individuals who by faith are saved by grace.
The Lord Jesus Christ died for sin so the believer can no longer be a slave to sin.
The justification is attained as a gift because of the righteousness of Jesus Christ on the cross and accounted by faith.
Jesus' resurrection proves He is the Son of God who has paid the believers sin debt and opened heavens glory.
Israel's 3 main feasts establish their spiritual calendar declaring personal salvation(spring), future church(summer), and global proclamation (fall)
The Jew and the Christian are both save by faith, not works. God uses Israel as a physical example of spiritual truth.