Should Christians remember Jewish holy days?

Most Christians do not celebrate the Jewish holy days and festivals, much less even know what they are. Should this be the case?

With Passover, we know that Jesus remembered the Passover every year and that the early Church celebrated it as well. God says to Moses in Exodus 12, "This day shall be a day of remembrance for you. You shall celebrate it as a festival to the Lord; throughout your generations you shall observe it as a perpetual ordinance." and "You shall observe the festival of unleavened bread, for on this very day I brought your companies out of the land of Egypt: you shall observe this day throughout your generations as a perpetual ordinance." Moses relays this message to the elders of Israel. And as we know, the Jews continue this ordinance even until today.

Now, as Christians, most of us are not biological descendants of Israel but are Gentiles, yet Paul writes that we are grafted into the same tree. In Romans 11, he writes "If some of the branches have been broken off, and you, though a wild olive shoot, have been grafted in among the others and now share in the nourishing sap from the olive root, do not boast over those branches. If you do, consider this: You do not support the root, but the root supports you."

So these ordinances of God should be for us as well. Now, Paul does excuse Gentiles from portions of the law, such as the food requirements, because we are of a different culture. (Personally, I think this could/should be seen as John Wesley viewed sin, that it should not be a stumbling block to God's grace. That God's grace is so great that we must bring everyone to it and we can worry about the other stuff later. That receiving the grace of God is not dependent on following the commands of God, but one who receives the grace of God should follow the commands of God.) But I do not think that this would carry over to us not remembering the festival of Passover.

How many of us remember the Sabbath and keep it holy? "Remember the Sabbath day by keeping it holy. Six days you shall labor and do all your work, but the seventh day is a Sabbath to the Lord your God. On it you shall not do any work, neither you, nor your son or daughter, nor your manservant or maidservant, nor your animals, nor the alien within your gates. For in six days the Lord made the heavens and the earth, the sea, and all that is in them, but he rested on the seventh day. Therefore the Lord blessed the Sabbath day and made it holy." I know that I do not, I regularly work either at work or at home on the Sabbath, whether it is celebrated on the Jewish Sabbath or on Sunday.

Christians are often the strongest proponents of displaying the 10 Commandments, yet how many even make an attempt at following them?

Perhaps someone could help me with understanding Yom Kippur. I know that it is the Day of Atonement, as ordained in Leviticus 16. It talks about that the people will be atoned for their sins, so I am not sure if it would continue into Christianity as we celebrate (should) our atonement whenever we gather with the partaking of the Lord's Supper. However, in Acts 27:9, we see that it was still done by the early Church.

With Hanukkah, I believe we see that Jesus celebrated it as described in John 10:22. (The festival of Dedication is Hanukkah, correct?) But I guess it is no surprise that a Jew celebrates a Jewish holiday. But are those who are grafted in exempt?

We see a very important reason in keeping these festivals and holy days, God says that we are to do it to remember what He has done. Could we remember it by another way? Sure, but God has told us how He wants us to remember them. When you go through the Bible, we see the words remember over and over and over. God remembers us and His promises and tells us to remember what He has done. Christians are not exempt.