For neither is circumcision anything, nor uncircumcision, but a new creation.Galatians 6:15(NASB)
Paul's emphasis in his Galatian epistle was that we are saved by grace through faith and we are to live the same way. We are saved by grace through faith and not by works of the Law... AND we are also to live by grace through faith and not by keeping religious rules or partaking in legalistic practices or cultural customs. We are not saved by works of the law or through man's merit - but by grace through faith in Christ.
A huge transition had to take place within the early Christian Church. Up until Christ's crucifixion, those who believed God's Word were looking forward to a coming Messiah. Before the Cross, people were born under the Law. They believed that God would send a Kinsman-Redeemer Who would redeem His people and save them from their sin. However, before the Redeemer arrived to pay the price of sin, their trespasses would have to be covered by the shed blood of innocent animals - but only covered, for it is impossible for the blood of bulls and goats to completely take away sins.
Until He arrived, God gave His people a series of feast days and specific sacrifices that pointed to their promised Messiah. He gave them an earthly priesthood and kingdom in anticipation of the Saviour's heavenly Priesthood and eternal Kingship. Before the Cross, the people were anticipating a coming Kinsman-Redeemer - and His name is JESUS.
Before the Cross, the people were still living under the Mosaic Law - in the dispensation of Law. Day by day, the Law reminded them that they were sinners in need of a Saviour, for no one could reach the impossibly perfect standard the Law required. But like Abraham and other men of faith... those that trusted God's Word and believed His promises were credited with righteousness - as they looked forward to the coming Messiah Who would redeem them from Satan, sin, death, and hell.
Daily sacrifices and the Lord's annual feast-days were a constant reminder that all have sinned and all need a Saviour - for all sin has a price to be paid. Paul reminded these believers that the Law was God's tool to show us that we are all sinners. It was a school-master to bring us to Christ, the sinless Lamb of God Who, by His own death, would take away the sin of the world. And 4000 years after Adam sinned, God sent His only begotten Son to pay the price for the sin of the whole world... so that whoever trusted in the death, burial, and resurrection of the Lord Jesus Christ, would be saved.
Those who looked forward to the coming Messiah, in the dispensation of the Law were saved by grace through their faith, which was reckoned as righteousness. We who look back to the Cross, in this dispensation of grace, are also saved by grace through faith - and we too are reckoned as righteous. And our salvation was bought and paid for by the shed blood of Jesus Christ.
The Cross of Christ was the pivotal point in history when the curse of the Law was broken and the price of sin was paid for in full. The shed blood of Christ was history's defining moment... when the icy grip of death on the throat of humanity was supernaturally broken by Christ's sacrificial death and glorious resurrection.
Before the Cross, the curse of the Law was on all men - Jew and Gentile alike. But God chose Israel to be His own people. He redeemed them from Egypt and adopted them as His own sons. Israel was chosen to be the one way through which mankind could be redeemed, for the Messiah was to be born from the seed of Abraham, through the tribe of Judah, of the house of David.
However, the only way for Gentiles to approach God in Old Testament times, was to become a Jewish proselyte and maintain strict adherence to Israel's laws and customs which included circumcision, adherence to the ongoing cycle of feast-days, following the food-laws, and through the year-by-year Day of Atonement - whereby the blood of sheep and goats temporarily covered the sin of the people - until the promised Messiah would come to offer Himself as the full and final ransom payment for the sin of the world.
Before the Cross, the Gentile nations were excluded from salvation - unless they became a Jewish proselyte. But following the Cross, the barrier that had existed between Jew and Gentile was broken-down forever, such that circumcision became an unnecessary ritual. Paul writes, "circumcision is of no consequence and uncircumcision is not anything... because in Christ there is a new Creation - old things are passed away and all things are become new."
Sadly, then as now, there are those that Paul calls 'Judaisers', who insist that post-Cross Christians are required by God to follow the same rites and rituals as pre-Cross believers, in order to be saved. They insist that salvation depends on keeping the Law in addition to believing on the death, burial, and resurrection of Christ, for the forgiveness of sins and life everlasting. But this is unbiblical, this is a false gospel, and this is Paul's emphasis in his Galatian epistle, "that neither is circumcision anything, nor uncircumcision, for we are all part of a new creation - in Christ."
The old, fallen creation in Adam and Israel's pre-Cross rites and rituals pointed to CHRIST - Whose sacrifice has paved the way for a new, redeemed creation in Christ. Old things are passed away - behold all things are become new.
Heavenly Father, thank You for the wonderful way that You gradually opened-up our understanding through the Old and New Testament Scriptures, to teach us that we are all sinners in need of a Saviour, and we are justified by faith. Thank You that You have broken down the barrier between Jew and Gentile and that that by grace through faith in Christ, we are new, redeemed creatures, and part of the one new-man in Him. May I live my life to Your praise and glory. In Jesus' name I pray, AMEN.