“O L-RD, great and awesome G-d, Who keeps His covenant and mercy with those who love Him, and with those who keep His commandments, we have sinned and committed iniquity, we have done wickedly and rebelled, even by departing from Your precepts and Your judgments. Neither have we heeded Your servants the prophets, who spoke in Your Name to our kings and our princes, to our fathers and all the people of the land. O L-RD, righteousness belongs to You, but to us shame of face, as it is this day, to the men of Judah, to the inhabitants of Jerusalem, and all Israel, those near and those far off in all the countries to which You have driven them, because of the unfaithfulness which they have committed against You. O L-RD, to us belongs shame of face, to our kings, our princes, and our fathers, because we have sinned against You. To the L-RD our G-d belong mercy and forgiveness, though we have rebelled against Him. We have not obeyed our G-d, to walk in His laws, which he set before us by His servants the Prophets.”
~ Daniel 9:4-10
Do we REALLY want to know the truth, so that it can set us free?
The departure from Torah began slowly, but was later legislated. In the first century AD, even before the Romans persecuted the Christians as Christians, the Romans persecuted the Jews as a result of Jewish rebellions against the empire. At that time, even the Gentile Christians were persecuted along with Jews because they worshipped with Jews and like Jews. Then, largely because Christians refused to rally behind a false Messiah named Bar-Kochba in a new rebellion, non-believing Jews expelled all Christians from their synagogues for their dis-loyalty, see also Council of Jamnia. Ironically, now Christians who had been persecuted by the Romans for being viewed as Jewish had been rejected by the Jewish establishment. (See also Early Christian Persecution.) Despite the fact that Christianity was a sect of Judaism that believed Jesus to be the Jewish Messiah, this turn of events forced Christians to view themselves as separate from the mainstream Jewish establishment for the first time, see also Rejection of Jesus. Some Gentile factions in the church used this expulsion to make it easier to justify distancing themselves from Torah-related practice, which identified them with Jews, in order to avoid Roman persecution for being Jewish.
Eventually, the seeds of this rejection of “Jewishness” took root when the Roman emperor Constantine I became the first Christian emperor in the early 4th century AD. He embraced some elements of Christianity early in his reign, although his views evolved throughout his life and he was ever tolerant to paganism. Under Constantine, the Roman church officially decreed that all Christians should observe Jesus’ resurrection separately from Passover (which the Latins called Quartodeciman) and that Jewish customs (i.e, anything Passover-related) should not be followed in regard to this holiday.  At the First Nicean Council, at which this was determined, Constantine declared, “It is unbecoming that on the holiest of festivals we should follow the customs of the Jews; henceforth let us have nothing in common with this odious people.” Shortly afterward, under the Christian empire, the church Council of Laodicea [see Revelation 3:14-22] strictly prohibited Christians from observing the Sabbath as described in the Torah and Constantine made Sunday a civil holiday and “Christian Sabbath.”
Carroll summarizes these events:
“It took the order of Constantine […] and decrees of the fourth-century Church councils to draw fast distinctions between Jewish and Christian observances, but the purpose of such decrees was to clarify the minds of Christians, who continued to think of themselves as Jewish.
The momentum and natural inclination of Christians had been to observe the holidays that Jesus and the apostles had observed. Historical evidence strongly suggests that the change in Passover to Easter and the re-definition of Sabbath were not based on the teaching of the apostles, but rather were motivated by other non-Biblical rationale. Quotes of Constantine and other early church fathers  reveal that anti-Semitism played a major role in these changes. The motivation to conform Christianity to paganism to make it more palatable to the Roman public has also been suggested.”
~ part of article from Wikipedia (emphasis added)