Throughout the history of God's people, two observances have repeatedly come under attack: the weekly Sabbath and the Passover. Satan has worked across centuries to distort or eliminate these, understanding that if he succeeds in turning people from the Sabbath, the holy days fall as well, severing the identifying sign between God and His people. The Passover has suffered similar assaults in nearly every generation, most notably in the Quartodecimani Controversy of the second and third centuries AD, when the western church under the bishop of Rome abolished the fourteenth-day observance altogether, replacing it with an Easter commemoration following Good Friday. Those who continued keeping Passover on the fourteenth were branded as Judaizers, scandalized, and in some cases persecuted by the power of the state, though the eastern churches of Asia Minor preserved the original observance. Even before Christ, the Jews themselves had already altered the festival, shifting it from the fourteenth day to the fifteenth and merging it with the Days of Unleavened Bread, thereby collapsing an eight-day observance into seven days—or, in some reckonings, even six. This tampering raises the question of why Satan would expend such effort on a single festival, unless it held exceptional importance to God's purpose. The answer lies in recognizing that the Passover is the very foundation of the covenant relationship between God and His people, both old and new. In the Old Covenant, God began His relationship with Israel on the Passover; in the New Covenant, Jesus Christ established the relationship for Christians on the last Passover night of His life by introducing new symbols to commemorate His sacrifice as the true Passover Lamb. At that final meal, recorded in Matthew 26, Jesus took bread and wine and declared them to represent His body and His blood of the new covenant, shed for the remission of sins, commanding His followers to "do this in remembrance of Me." This institution of new symbols was not an arbitrary innovation but the fulfillment of what the Passover lamb had typified for some fourteen or fifteen hundred years—Christ Himself, the Lamb of God slain from the foundation of the world. Just as the Old Testament sacrifice of the lamb and the blood on the doorposts secured physical deliverance from the death angel, the New Testament symbols of bread and wine, instituted by Christ, secure spiritual deliverance through the forgiveness of sins. Crucially, the name "Passover" itself is tied to God's act of passing over the houses of Israel, not to the exodus from Egypt. Exodus 12 and the testimony of Josephus confirm that the Passover sacrifice commemorates the passing over, while the Feast of Unleavened Bread, a separate observance beginning the following day, commemorates the departure from Egypt. Recognizing this distinction clarifies why the Jewish blending of these two separate events into one seven-day festival constituted a significant alteration of God's original instruction, paralleling the later Catholic replacement of Passover symbols with Easter observances—both representing attempts across history to obscure or change the God-ordained memorial established first through the lamb's blood and later through Christ's own body and blood.