In our communion liturgy as we consecrate the elements, we say: "Take and drink, this is the new testament of my blood, shed for the forgiveness of all your sins..."
What is new here?
The old testament, or covenant, required the spilling of blood. Sacrifices were required and blood was shed for the sins of the people.
When Jesus met with His disciples on the Thursday night of what we call Holy Week, Jesus institued a new testament or covenant. It also required the spilling of blood. But it would not be the blood of lambs and other animals. It would be His blood! Jesus would be the once and for all time sacrifice, sufficient to cover the sins of the whole world.
Jane Fryer captures this idea in the "Today's Light Bible," when she writes, He (Jesus) had to come to us; we could not go to Him. The old covenant wasn't flawed, we were. We could not keep God's commandments. We could not even want to do that. (page 1671).
So, carrying out the will of His Father, Jesus came down to us from heaven, lived the perfect life we could not and did not want to live, suffered for our sins on the altar of the cross, paid in full for our redemption, and opened the gates of heaven to all who would believe in His one atoning sacrifice.
Makes you want to celebrate Easter that much more, right?