why is everyone ignoring my previous post?
Well, in part because I hadn't even seen this thread until now.
But, also, having read it, in part because it seems you perceive that testimony from places like the link you provided are actually capable of "proving" something.
I submit to you that they "prove" nothing, even when all of their information is accurate, and in this case I suspect that if you looked closely at what they posted you would disagree with the accuracy of some of their assertions as well, for instance the link claims that Jesus (pbuh) sinned. Since when do Muslims believe that of their prophets. So, the link is suspect; I believe that without proper evaluation of the truth of the information they present, they just throwing everything at a point hoping something will stick. And when people use such links as integral to their own question/positions, well, I tend to dismiss them in the same way I dismiss the value of the link itself.
But, since you asked a second time, I will address your question in two parts: "Why do Christians celebrate Easter?"
First, speaking for myself. I celebrate Easter, because Easter is a celebration of the resurrection of Jesus Christ. This is an event which I believe did in fact take place. I believe that Jesus was crucified, died, and was buried. And I believe that on the first day of the week Jesus was raised to life again. I believe that the event of the resurrection is testimony to who Jesus is -- Lord, God, and Messiah. I believe that the event of the resurrection is the fulfillment of the recognition by God the Father that Jesus fulfilled the sianatic and levitical commands, kept Torah, and has brought to completion the work of reconciliation between God and humankind that was the central purpose for the covenants recorded in the Tanakah. I believe that the event of the resurrection is the proof of God's intention and ability to restore the world, and event that will be brought to final fruition when Christ returns to more fully establish God's kingdom on earth, but that in the resurrection the etermal kingdom has already in a sense broken into our present day existences so that we are already living in the first days of a new creation. And I celebrate Easter because I believe all of these things are worth celebrating.
Second, implicit in your question and several of your posts seems to be doubt that the resurrection (or for that matter the crucifixion) ever took place. While I don't expect to change your mind in that regard, I respectfully disagree with such a conclusion. And I find the presumption that it must be false or has been "proven" false merely because someone with an agenda has questioned certain aspects of it as being historical facts to be more than a little impudent. Absent a time machine, I believe that there is far more to support the thesis that Jesus died as a result of Roman execution, than any of the alternatives that have been presented over the course of time. But even if the crucifixion could not be shown to be completely verifiable, I would still believe in the reality of the resurrection.
One need not go further than your own question, "Why do Christians....", to recognize that Christianity exists. Do you understand, that at the heart of Christianity is the Resurrection? Why did Christianity arise, and why did it take the shape it did? The answer to this lies in the belief that something unique had taken place in not just the teaching of Jesus Christ, but in his death and resurrection. Let me categorically assert--There is no form of early Christianity known to us -- though there are some that have been invented by ingenious, yet disingenuous, scholars -- that does not affirm at its heart that after Jesus' shameful death God raised him to life again.
(credit to biblical scholar N.T. Wright for the genesis of that last sentence) Even before the time of Paul, the earliest written witness, the resurrection is woven into the very fabric of early Christian life and thought effecting everything that the nascent church did. The sacraments, received by Paul from others, where memorials of Jesus' death and resurrection and were conducted as spiritual re-enactments of these events.
Christianity began as a resurrection movement. It was not just a belief that Jesus had been raised up from the dead, but that the OT apocalyptic general "resurrection of the dead" had begun. The book of Acts tells an interesting story in this regard:
The priests and the captain of the temple guard and the Sadducees came up to Peter and John while they were speaking to the people. They were greatly disturbed because the apostles were teaching the people and proclaiming in Jesus the resurrection of the dead. (Acts 4:1-2)
Note that Peter and John are not just telling people that Jesus had been raised (though that was the content of the first ever Christian sermon), but that in Jesus there was also occuring this "resurrection of the dead." Now, the Jews had already formulated specific ideas as to what that meant. From the time of Ezekiel 37 onward (about 500 BC),
the resurrection was an image used to denote the great return from exile, the renewal of the covenant, and to connote the belief that when it happened it would mean that Israel's sin and death (i.e. exile) had been dealt with, that YHWH had renewed his covenant with his people. Thus, "the resurrection of the dead" became both metaphor and metonymy, both a symbol for the coming new age and itself, taken literally, one central element in the package. When YHWH restored the fortunes of his people then of course Abraham, Isaac, and Jacob, together with all God's people...would be reembodied, raised to life in God's new world.
If, therefore, you had said to a first-century Jew "the resurrection has occurred," you would have received the puzzled response that it obviously had not, since the patriarchs, prophets and marytrs were not walking around alive again and since the restoration spoken of in Ezekiel 37 had not clearly occurred either.
The Challenge of Easter, N.T. Wright, Intevarsity Press, c. 2009
The very earliest church roundly declared not only that Jesus had been raised from the dead but that "the resurrection of the dead" had already occurred.
Without Jesus' resurrection as the impetus for this belief, there is no reason for first-century Jews to have believed this climatic event to have begun. They did not behave as if they had had a new sort of religious experience or as if their former leader was alive and well in the presence of God. They behaved as though a new age had arrived--though not in the way they have been preconditioned to think of it. So, this new age belief had been triggered by something they had not expected. Nothing was less expected by the disciples than that Jesus would have been crucified, nothing except that having been so executed at the hands of the Romans that he would have returned from the grave to bodily life again. Against all their expectations of
all the righteous dead of God being raised to life again at the
end of time, they experienced
one person being raised to life again in the
middle of the present age. And this, not only unbelievable but unanticipated story, is the one they chose to tell. If they were going to invent something, this is not the story they would have invented.
I contend, it is impossible to explain why the early church continued to believe and put forth the idea that Jesus was the Jewish Messiah if he had simply been executed in the manner of all the other failed messiahs. There would be no hearing for failed Messiahs in the Jewish world, and no concern about Messiahs at all in the Gentile world. But, this is how the church chose to present Jesus. The only substantiation they ever gave for doing so was their belief in his resurrection.
I can understand why people doubt the authenticity of that story. But take away the message of Easter and you don't have a Christian faith. The question isn't just if there was no resurrection where did that faith come from? But even more, if there was no resurrection, where did a church preaching the resurrection as the center piece of their faith come from, and how did it emerge within first-century Judaism and become known in Rome even before the time of Paul?