Before Jesus ascended into heaven, He instructed his disciples to go into all the world, preach the Gospel, and teach His commandments. The disciples of Jesus did as they were instructed and had great success sharing the good news of Jesus in the Gentile nations.
There was a group of pharisees who also believed in Jesus but had not been personally discipled by Him. They had witnessed the crucifixion of Jesus and the outpouring of the Holy Spirit on the Day of Pentecost and at some point, had chosen to believe in Jesus. They wanted to be a part of the Great Commission, so they went out preaching the good news about Jesus. The only problem was, they were not teaching the instructions of Jesus. They were still teaching the instructions of Moses, telling Gentile believers in Jesus that in order to be recipients of the promises of God, they must become a part of Israel; therefore, they must be circumcised and keep the law of Moses.
The word Judaize refers to the process of making a Gentile into a Jew or converting non-Jewish people to Judaism. Prior to Jesus, this was the customary method for converting Gentiles to the Jewish faith. These pharisees were labeled Judaizers because in the jurisdiction of the New Covenant, they were still trying to convert Gentiles to their religious way of thinking. It is understandable that these early church Judaizers were simply ignorant of God’s New and better Covenant and did not understand that New Covenant believers were not subject to the instructions of the Old Covenant. God was not requiring Gentiles to convert to Judaism, and He was not requiring Gentiles to become Jews to be saved.
The Bible has a lot to say about Judaizers and their false gospel message. The entire book of Galatians was written to rebuke and correct the false teaching of these early church Judaizers. Galatians 1:6-7 refers to the gospel of the Judaizers as “another gospel” which is really no gospel at all. Galatians 1:8-9 says that all who preach this Torah-based gospel are under a curse. This is the only curse pronounced in New Testament scriptures. Galatians 3:1 tells us that those who received and believed in this Torah gospel had been “bewitched,” and Galatians 5:4 says those who adhere to this Judaizer theology have “fallen from grace.”
The original New Testament Judaizers were a sect of the pharisees who believed in Jesus but did not understand covenantal jurisdiction. These were circumcised Jews teaching uncircumcised Gentile believers in Jesus that they must be circumcised and keep the law of Moses.
In contrast, these modern day Judaizers (Sabbath Keepers) are uncircumcised Gentiles, teaching other uncircumcised Gentile believers in Jesus that they must be circumcised and keep the law of Moses.
When the early church Judaizers tried to teach Gentile converts to Christianity that they must be circumcised and keep the law of Moses, they were rebuked by the disciples of Jesus. These disciples, now apostles, had personally been taught by Jesus and entrusted to lead His new church.
This issue was settled 2,000 years ago. Believers in Jesus are not subject to the Old Covenant law of Moses.