why was Jesus head not just cut off or neck slit like the past sacrifices unto God with lambs and goats?
why was he beaten and dragged and SLOWLY put to death.

If we really needed his sacrifice to get into heaven and his righteous blood as a offering. Why not a quick death, and he rises again in 3 days?

why is his sacrifice different from the other sacrifices? Why not just cut his neck and let it drain quickly from his body, or cut his head off? same thing right? a sacrifice?

Jesus was an invalid sacrifice.
The Torah doesn’t allow human sacrifices.

theone78: No messianic prophecy expects The Messiah
to be an atonement for the sins of anyone else.

DougLawrence: that’s only speculation. ‘Satan’ only appears after Jesus is sent by the spirit into the wilderness. The character makes no future appearances as given by the authors of the Gospels too back up that he manipulated ‘the Jews’ or Romans into leading Jesus too his crucifixion. Jesus was far from being ‘sinless’.
References :
http://www.geocities.com/b_r_a_d_99/counterfeitpriest.htm
http://www.geocities.com/b_r_a_d_99/polish.htm
http://www.messiahtruth.com/sinless.html

His sacrifice was one of humiliation, turned glory. Crucifixion was one of the most demeaning form of execution, but Jesus needed to completely humble himself and suffer as human in order to mollify the sins of humanity.
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To have your head cut off in the Roman Empire, you had to be a citizen. Paul was beheaded. However, as Jesus was not a citizen, he had to be crucified, which was in accordance with Roman Law.

Taking an animal to the Temple was a deliberate sacrifice, known to be by the sinner and the priest. However, the Roman authorities had no idea that Jesus was a sacrifice. They killed him the way they killed any other criminal.
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The Jesus story is of disputable history (Christians believe this story reflects actual events, others assert that inconsistencies in the biblical time-line with more reliable sources make it impossible). If the story is a myth, it makes sense to use a more brutal form of punishment in the story to garner more sympathy and increase drama. If the story is true (at least in part, ie the execution (not buying magic juju)), remember that Jesus was put to death by Romans, who wanted him to suffer as a deterrent to other rebels. The Roman government was not adverse to torturous deaths for those they viewed as criminals, which is how the Romans would have viewed such situations, not as religious sacrifices.

If your question is more on line with theological issues with the idea of god allowing/planning cruelty look up The Problem of Evil, which is a paradox origionally asserted by Epicurus which states "If God has the power to stop evil but does not want to, then he is not omnibenevolent. If God wants to stop evil but does not have the power, then he is not omnipotent." More here http://en.wikipedia.org/wiki/Theodicy.
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