The resurection is the crux of Christianity.
It’s been ripped off by a few other religions, and there’s been a whole lot of spinning other religious traditions to make them look similar but neither of those changes the fact.
Well, there was Mithra... some say we ripped off Christ from that.
Even we Proddies recognize a good solution when we see it!
As pointed out earlier, the death of Christ which provided atonement for the sins of man is the essential point of Christianity. We are told to observe Christ's death until he comes again.
1Co 11:26 For as often as you eat this bread and drink the cup, you proclaim the Lord's death until He comes
Rom 6:3 Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death?
The resurrection gives great hope that we too can be eternal, but everyone is going to be resurrected anyways, some in a good way and some in a bad way:
Joh 5:29 And shall come forth; they that have done good, unto the resurrection of life; and they that have done evil, unto the resurrection of damnation
And the bible NEVER tells us to observe the resurrection of Christ and especially never says to do it at the expense of the holy days that the Lord Jesus Christ created.