The Judaizers were a faction of the Jewish Christians, both of Jewish and non-Jewish origins, who regarded the Levitical laws of the Old Testament as still binding on all Christians. They tried to enforce Jewish circumcision upon the Gentile converts to early Christianity and were strenuously opposed and criticized for their behavior by the Apostle Paul, who employed many of his epistles to refute their doctrinal positions.

The term is derived from the Koine Greek word (), used once in the Greek New Testament (),Greek New Testament, Galatians 2:14 ἀλλ᾽ ὅτε εἶδον ὅτι οὐκ ὀρθοποδοῦσιν πρὸς τὴν ἀλήθειαν τοῦ εὐαγγελίου εἶπον τῷ Πέτρῳ ἔμπροσθεν πάντων Εἰ σὺ Ἰουδαῖος ὑπάρχων ἐθνικῶς ζῇς καὶ οὐκ Ἰουδαϊκῶς τί τὰ ἔθνη ἀναγκάζεις Ἰουδαΐζειν. when Paul publicly challenged the Apostle Peter for compelling Gentile converts to early Christianity to "judaize".Michele Murray Playing a Jewish Game: Gentile Christian Judaizing in the First and Second Centuries CE, Canadian Corporation for Studies in Religion, 2004, p. 33: "From Paul's perspective, by withdrawing from Gentile table fellowship, Peter was sending a message to the Gentile believers of Antioch. The message to Antiochene Gentile Christians was that they were to judaize." This episode is known as the incident at Antioch.

Most Christians believe that much of the Old Covenant has been superseded, and many believe it has been completely abrogated and replaced by the Law of Christ. The Christian debate over judaizing began in the lifetime of the apostles, notably at the Council of Jerusalem and the incident at Antioch. It has been carried on parallel to continuing debates about Paul the Apostle and Judaism, Protestant views of the Ten Commandments, and Christian ethics.

Origin The meaning of the verb judaize,from the Koine Greek Ioudaizō (Ιουδαϊζω); see also Strong's G2450 from which the noun Judaizer is derived, is derived from its various historical uses. Its biblical meaning is inferred and is not clearly defined beyond its obvious relationship to the word "Jew". The Anchor Bible Dictionary, for example, says: "The clear implication is that gentiles are being compelled to live according to Jewish customs."Anchor Bible Dictionary, Vol. 3. “Judaizing.”

The word Judaizer comes from judaize, which is seldom used in English Bible translations (an exception is the Young's Literal Translation for Galatians 2:14).

In the Early Church

The Council of Jerusalem is generally dated to 48 AD, roughly 15 to 25 years after the crucifixion of Jesus, between 26 and 36 AD. Acts and Galatians both suggest that the meeting was called to debate whether male Gentiles who were converting to become followers of Jesus were required to become circumcised; the rite of circumcision was considered execrable and repulsive during the period of Hellenization of the Eastern Mediterranean and was especially adversed in Classical civilization both from ancient Greeks and Romans, which instead valued the foreskin positively. Many ancient people in these cultures used epispasm to restore their foreskins so as to not stand out amongst the Hellenists.

Before Paul's conversion, Christianity was part of Second Temple Judaism. Gentiles who wished to join the early Christian movement, which at the time comprised mostly Jewish followers, were expected to convert to Judaism, which likely meant submission to adult male circumcision for the uncircumcised, following the dietary restrictions of kashrut, and more. During the time period there were also "partial converts", such as gate proselytes and God-fearers (i.e. Greco-Roman sympathizers who made an allegiance to Judaism but refused to convert and therefore retained their Gentile (non-Jewish) status), hence they were uncircumcised and it was not required for them to follow any of the commandments of the Mosaic Law.

The inclusion of Gentiles into early Christianity posed a problem for the Jewish identity of some of the early Christians: the new Gentile converts were not required to be circumcised nor to observe the Mosaic Law. Circumcision in particular was regarded as a token of the membership of the Abrahamic covenant, and the most traditionalist faction of Jewish Christians (i.e., converted Pharisees) insisted that Gentile converts had to be circumcised as well. Paul insisted that faith in Christ (see also Faith or Faithfulness) was sufficient for salvation, therefore the Mosaic Law was not binding for the Gentiles.

New Testament

In the New Testament, the Judaizers were a group of Jewish Christians who insisted that their co-religionists should follow the Mosaic Law and that Gentile converts to Christianity must first be circumcised (i.e. become Jewish through the ritual of a proselyte). Although such repressive and legalistic requirements may have made Christianity a much less appealing religious choice for the vast majority of Gentiles, the evidence afforded in Paul's Epistle to the Galatians exhibits that initially a significant number of the Galatian Gentile converts appeared disposed to adopt these restrictions; indeed, Paul strenuously labors throughout the letter to dissuade them from doing so (cf. , , , ).

Paul was severely critical of the Judaizers within the early church and harshly reprimanded them for their doctrines and behavior. Paul saw the Judaizers as being both dangerous to the spread of the Gospel and propagators of grievous doctrinal errors. Many of his letters included in the New Testament (the Pauline epistles) contain considerable material disputing the view of this faction and condemning its practitioners. Paul publicly condemned Peter for his seemingly ambivalent reaction to the Judaizers, embracing them publicly in places where their preaching was popular while holding the private opinion that their doctrines were erroneous (cf. , , , , , , ).

That Gentile Christians should obey the Law of Moses was the assumption of some Jewish Christians in the early church, as represented by the group of Pharisees who had converted to Christianity in . Paul opposed this position, concluding that Gentiles did not need to obey to the entire Law of Moses in order to become Christians. The conflict between Paul and his Judaizing opponents over this issue came to a head with the Council of Jerusalem. According to the account given in Acts , it was determined by the Great Commission that Gentile converts to Christianity did not have to go through circumcision to be saved; but in addressing the second question as to whether or not they should obey the Torah, James the Just, brother of Jesus encouraged the Gentiles to "abstain from things sacrificed to idols, and from blood, and from things strangled, and from fornication" ().

Paul addresses this question in his Epistle to the Galatians, in which he condemned those who insisted that circumcision had to be followed for justification as "false believers" ():

Paul warns the early Galatian church that gentile Christians who submit to circumcision will be alienated from Christ: "Indeed I, Paul, say to you that if you become circumcised, Christ will profit you nothing. And I testify again to every man who becomes circumcised that he is a debtor to keep the whole law. You have become estranged from Christ, you who attempt to be justified by law; you have fallen from grace." ().

The Catholic Encyclopedia notes: "Paul, on the other hand, not only did not object to the observance of the Mosaic Law, as long as it did not interfere with the liberty of the Gentiles, but he conformed to its prescriptions when occasion required (). Thus he shortly after circumcised Timothy (), and he was in the very act of observing the Mosaic ritual when he was arrested at Jerusalem ( sqq.)."

Circumcision controversy

Paul, who called himself "Apostle to the Gentiles", criticised the practice of circumcision, perhaps as an entrance into the New Covenant of Jesus. In the case of Timothy, whose mother was a Jewish Christian but whose father was a Greek, Paul personally circumcised him "because of the Jews" that were in town.McGarvey on Acts 16: "Yet we see him in the case before us, circumcising Timothy with his own hand, and this 'on account of certain Jews who were in those quarters.'" Some believe that he appeared to praise its value in , yet later in Romans 2 we see his point. In he also disputes the value of circumcision. Paul made his case to the Christians at Rome that circumcision no longer meant the physical, but a spiritual practice. He also wrote: "Circumcision is nothing and uncircumcision is nothing. Keeping God's commands is what counts."

Later Paul more explicitly denounced the practice, rejecting and condemning those Judaizers who promoted circumcision to Gentile Christians. He accused them of turning from the Spirit to the flesh: "Are you so foolish, that, whereas you began in the Spirit, you would now be made perfect by the flesh?" Paul warned that the advocates of circumcision as a condition of salvation were "false brothers". He accused the advocates of circumcision of wanting to make a good showing in the flesh, and of glorying or boasting of the flesh. Paul instead stressed a message of salvation through faith in Christ opposed to the submission under the Mosaic Law that constituted a New Covenant with God, which essentially provides a justification for Gentiles from the harsh edicts of the Law, a New Covenant that did not require circumcision (see also Justification by faith, Pauline passages supporting antinomianism, Abrogation of Old Covenant laws).

His attitude towards circumcision varies between his outright hostility to what he calls "mutilation" in to praise in . However, such apparent discrepancies have led to a degree of skepticism about the reliability of Acts.For example, see Catholic Encyclopedia (1907–1914): Acts of the Apostles: Objections Against the Authenticity Baur, Schwanbeck, De Wette, Davidson, Mayerhoff, Schleiermacher, Bleek, Krenkel, and others have opposed the authenticity of the Acts; an objection is drawn from the discrepancy between and . Some believe that Paul wrote the entire Epistle to the Galatians attacking circumcision, saying in chapter five: "Behold, I Paul say unto you, if ye be circumcised, Christ shall profit you nothing."

The division between the Jews who followed the Mosaic Law and were circumcised and the Gentiles who were uncircumcised was highlighted in his Epistle to the Galatians:

Extra-biblical sources "Judaizer" occurs once in Josephus' Jewish War 2.18.2, referring to the First Jewish–Roman War (66–73), written around 75:

It occurs once in the Apostolic Fathers collection, in Ignatius's letter to the Magnesians 10:3 written around 100: Judaizing teachers are strongly condemned in the Epistle of Barnabas. (Although it did not become part of the Christian Biblical canon, it was widely circulated among Christians in the first two centuries and is part of the Apostolic Fathers.) Whereas Paul acknowledged that the Law of Moses and its observance were good when used correctly ("the law is good, if one uses it lawfully", ), the Epistle of Barnabas condemns most Jewish practices, claiming that Jews had grossly misunderstood and misapplied the Law of Moses.

Justin Martyr (about 140) distinguishes two kinds of Jewish Christians: those who observe the Law of Moses but do not require its observance of others—with these he would hold communion—and those who believe the Mosaic law to be obligatory on all, whom he considers heretics (Dialogue with Trypho 47).

The Council of Laodicea of around 365 decreed 59 laws, #29: