Since we Messianic/Hebrew Roots people are constantly accused of this crime we thought it would be a good idea to post the standard definition of this false doctrine as provided by Phillip Schaff (the greatest of all Church Historians).
Phillip Schaff – History of the Christian Church, Volume I:
Apostolic Christianity. A.D. 1-100.
§ 73. Heretical Perversions of the Apostolic Teaching. page 478
1. The Judaizing tendency is the heretical counterpart of Jewish Christianity. It so insists on the unity of Christianity with Judaism, as to sink the former to the level of the latter, and to make the gospel no more than an improvement or a perfected law. It regards Christ as a mere prophet, a second Moses; and denies, or at least wholly overlooks, his divine nature and his priestly and kingly offices. The Judaizers were Jews in fact, and Christians only in appearance and in name. They held circumcision and the whole moral and ceremonial law of Moses to be still binding, and the observance of them necessary to salvation. Of Christianity as a new, free, and universal religion, they had no conception. Hence they hated Paul, the liberal apostle of the Gentiles, as a dangerous apostate and revolutionist, impugned his motives, and everywhere, especially in Galatia and Corinth, labored to undermine his authority in the churches. The epistles of Paul, especially that to the Galatians, can never be properly understood, unless their opposition to this false Judaizing Christianity be continually kept in view.
The same heresy, more fully developed, appears in the second century under the name of Ebionism.