Do Christians Need to Slaughter Lambs or Celebrate Passover?

At Eastertide, Christians  celebrate the resurrection of Jesus.  During the week leading up to it, they celebrate Palm Sunday, when Jesus entered Jerusalem in the back of a foal.  They celebrate "Holy Thursday" when Jesus celebrated Passover and had is "last supper" with his disciples and asked them to remember his death through eating bread and drinking wine.   On "Good Friday," they remember the Crucifixion of Jesus.  Finally on Easter Sunday, they celebrate Jesus resurrection.   All are deeply meaningful and important to their faith in Jesus.  

But must Christians celebrate Passover.  Must they slaughter Lambs to keep the festival?

Christians no longer need to kill lambs to celebrate Passover. Equally, Christians no longer need to celebrate Passover at all. In the New Covenant, where Jesus fulfills the Passover, Christ is ourPassover. But Jesus asked us to remember his death by breaking bread and drinking the cup. That was his institution of the practice of "The Lord's Supper." However, if Christians wish to celebrate the death and resurrection of Jesus by recalling how the Passover prefigured Christ's sacrifice of sin as our Passover lamb by recalling the original Passover, that is certainly within "Christian Liberty." We are free do to what ever is not contrary to God's word or God's will. But Jesus' church is not legally bound to do so.