The Atonement of Christ's Blood

What is the relationship between Jesus' sacrifice and our redemption, forgiveness and receiving an inheritance per the terms of the covenant / will that was effected by His death? From what, and to what, are we saved? Is it Jesus' death alone that saves us? What part does His resurrection have in our salvation? Does the justice of God demand the satisfaction of blood before He will forgive, similar to what pagans throughout history have believed? What was the purpose of the Old Testament sacrifices? Does blood alone atone for sin? How does Christ's death render powerless the devil? To whom was Christ's life given as a ransom? From what are we ransomed? Why did Jesus not only die, but suffer and die? If all that was necessary was His shed blood, why didn't God sovereignly ordain a more merciful death for His own dear Son? What is the relationship between a will or testament, and a covenant? What was willed to Jesus as an inheritance from His Father, and what was willed to us through the new testament in His blood?