God promised that there would come a man who would crush the ancient serpent, defeating once and for all time the rebellion of men and angels - though he himself would be bruised.
God commanded Abraham to sacrifice his only son, the son on whom all his hopes for the future were pinned, the son who was himself the fruit of God's promise - and then at the last minute, when hope was gone, stopped the knife and sent a ram instead.
God rescued his people from Egypt, but not without blood, for in truth their firstborn were not better than the firstborn of Pharaoh, and an animal had to die - the slain lamb painting the doorposts of the house, death on the outside and life within,
God gave his people animal sacrifices, rivers of blood through the generations, hands laid on goats to transfer sin and guilt - so that sin could be done to death, and sinfulness sent away to the wilderness.
God spoke to his people through the prophet Isaiah, at the point of their great rejection of him, and told them of his servant, the one would who would himself be rejected by the people - and yet would bear sin and transgression to death.
God sent his own Son into the world. Crucified, he achieved all that had been symbolised and promised. Here is Satan defeated. Here is the loving Father offering his only Son. Here is the rescue from sin by blood. Here is the sacrifice which does to death our rebellion and removes our guilt. Here is the Servant who submits to taste death for all.
O love of God! O sin of man!
In this dread act Your strength is tried;
And victory remains with love;
For Thou our Lord, art crucified!