The importance of Passover is often lost on many believers. There seems to be a general misunderstanding of this celebration. Often it is classified as a "Jewish Holiday". Many grafted-in believers see no reason to celebrate this special season.
This attitude is sadly the majority view. Few realize this attitude grew out of history and unfortunately bad teachings & Antisemitism of the 1st-4th century. Let's look at the History and the reasons for keeping Passover.
Passover was celebrated by the Messiah during His earthly life. His followers continued observing Passover for decades with many continuing several centuries. With the influx of large numbers of Gentiles and the Jewish revolts, most Congregations became Gentile lead by the second century. Gentile Bishops like Ignatius advocated moving Gentiles away from any Jewish Practices (including Shabbat).
By the mid to late second century, men like Marcion actively tried to separate the Faith in Messiah from the G-d of the "Old Testament" (Tanakh). While he was later declared a heretic, neo-Marcionism is still influencing the Church today. Gentile leaders, facing persecution from Rome, moved practices away from Judaism in an effort to avoid persecution being experienced by the Jews. This practice and separation culminated in 325 CE with Constantine forever altering the celebration of the resurrection from aligning with Passover. Additionally ordnances were passed in the Church forbidding believers from celebrating Passover.
The Joy and reason for Passover:
Passover is a celebration of G-d's deliverance of Israel from slavery. For a grafted-in believer Passover is not only deliverance from Egypt (through our spiritual father Abraham and his descendants), but also deliverance from the Slavery of Sin and Death. We have every reason to celebrate Passover: because Messiah did, because He commands us to, because we are grafted into Israel, and because of the freedom from sin that was brought forth on that day.
People rejoice of Resurrection Day, as they should, for He is risen, thus proving Adonai accepted the perfect sacrifice. We should also celebrate on Passover, for on that day our people were redeemed from Egypt; but even more importantly, we were freed from sin.
There is no Resurrection Day without Passover. It was on Passover that His blood was shed, it was on Passover that we where redeemed.
For Passover is even greater than Resurrection day, for it was on Passover that we became reconciled to G-d and the Adversary lost his claim to us.