“…that the blessing of Abraham might come upon the Gentiles in Christ Jesus, that we might receive the promise of the Spirit through faith”
This verse presents two purposes for Christ’s work on the cross as a curse for us (3:13): 1) the blessing of Abraham comes on the Gentiles by faith, and 2)we receive the Holy Spirit through faith.
that the blessing of Abraham might come upon the Gentiles in Christ Jesus,
God extended His blessing of faith that He gave to Abraham to the Gentiles as well. People who operate on faith like Abraham receive the blessing of Abraham. That blessing is justification by faith. The principle of justification by faith is the center of the Abrahamic Covenant (Genesis 15:6). The Gentiles do not receive eternal salvation by Jewish circumcision. They receive it the same way the first Jew [Abraham] received it–by faith.
that we might receive the promise of the Spirit through faith
“Promise” comes from two words: upon and to announce. God makes announcements of His grace based on His character. We cannot accumulate merit before God because we cannot gain enough quality or quantity to match the standard of God’s righteousness. Only God’s grace can give us that. This is true with receiving the Holy Spirit as well. The moment a person believes in Christ he receives the Holy Spirit. This is simultaneous with salvation, not consequent to salvation.
God always operates according to the standard of Himself.
Nothing less than perfection is the standard for one’s acceptance with God. No one can attain to that perfection. Therefore, we must throw ourselves on the forgiveness of the grace of the cross.