In his massive study of Jewish Influence on Christian Reform Movements , Louis Newman claims that the “Mosaic Books have never held a dominant place in orthodox Christianity; it is only among special groups that the Pentateuch has won adherence,” groups where “literal acceptance of the Code” was “a fundamental doctrine of their cult” (14).
He enumerates some these “special groups”: “the Abyssianians have made the New Testament pivotal in their system, but venerated and observed the laws of the Old Testament in order to profit by the blessing it was supposed to offer. The Passagii in the twelfth and thirteenth centuries denied the coming of Jesus abrogated the Pentateuchal legislation, and urged upon Christians the literal fulfillment o fall its precepts, except that with reference to sacrifices. The numerous Sabbatarian movements in Hungary, Bohemia, Moravia, Russia and England also demanded Christian adherence to Mosaic precepts. The Puritans in England and America, several sects on the Continent and in England, sought to restore to prominence in Christian life the principle of literal observance of the Jewish laws, oftentimes supplemented by Rabbinical injunctions. Some of these groups have required partial, others complete fulfillment of Mosaic rites” (14-15). Meanwhile, the “official church” has treated these groups as heretical.Newman is right so long as we keep in mind that he is talking about literal application of the laws of Moses. If we apply a looser criterion, though, the picture is more complicated. Though medieval law codes were not straightforward and literal applications of Mosaic law, they drew some inspiration from the Pentateuch. As Newman says, “The Carolingian state was strongly theocratic in character, and looked back to the glories not only of imperial Rome, but also of Judea and Israel” (33).
And a glance at virtually any medieval discussion of the Latin liturgy will indicate that worship was understood in the light of Mosaic regulations concerning priesthood, purity, sacrifice, vestments, and so on. At every point, Mosaic ceremonial rules were allegorically modified to fit the church, but the connection between the worship of old and new is made regularly.