Is it not enough to refrain from eating bread on Passover? Why do we make such an effort to remove bread products from our homes?
Even if one fulfills all the mitzvot associated with Pesach like eating matza and bitter herbs, telling the story of the Exodus in the Haggada, refraining from eating chametz, observing the laws of Yom Tov etc., but he maintained ownership of chametz, he would have transgressed very significant laws of Pesach. For this reason, one must take very seriously and make every effort to remove chametz from his ownership before the holiday commences.
The Torah states two separate prohibitions about chametz: “You shall not see it” (Ex. 13:7) and “You shall not posses it” (Ex. 12:19). This is in addition to the requirement, “By the first day, all chametz shall be removed” (Ex. 12:15). Hence, by midday of the 14th of Nisan, every Jew is required to dispose or relinquish ownership of all chametz in his property as well as that which he owns but is located in others’ domains. If he does not do so, at every moment of the festival he is transgressing these three commandments. In addition, any chametz that should have been disowned and wasn’t is prohibited indefinitely even after Pesach.