"You have heard in the story of the Passion how Christ is portrayed as our exemplar and helper, and that he who follows him and clings to him receives the Spirit, who will enable him also to suffer. But the words of Paul are more Christian and should come closer home to our hearts and comfort us more, when he says: "Christ was raised for our justification." Here the Lamb is truly revealed, of whom John the Baptist testifies, when he says in Jn 1, 29: "Behold, the Lamb of God, that taketh away the sin of the world." Here is fulfilled that which was spoken to the serpent: "I will put enmity between thee and the woman, and between thy seed and her seed: he shall bruise thy head," which means that for all those who believe in him, hell, death, and the devil and sin have been destroyed. In the same manner the promise is fulfilled to-day which God gave to Abraham, when he said in Gen 22, 18: "In thy seed shall all the nations of the earth be blessed." Here Christ is meant, who takes away our curse and the power of sin, death and the devil.
All this is done, I say, by faith. For if you believe that by this seed the serpent has been slain, then it is slain for you; and if you believe that in this seed all nations are to be blessed, then you are also blessed. For each one individually should have crushed the serpent under foot and redeemed himself from the curse, which would have been too difficult, nay impossible for us. But now it has been done easily, namely, by Christ, who has crushed the serpent once, who alone is given as a blessing and benediction, and who has caused this Gospel to be published throughout the world, so that he who believes, accepts it and clings to it, is also in possession of it, and is assured that it is as he believes. For in the heart of such a man the Word becomes so powerful that he will conquer death, the devil, sin and all adversity, like Christ himself did. So mighty is the Word that God himself would sooner be vanquished than that his Word should be conquered."
From an Easter sermon by Martin Luther on Mark 16:1-8, from his Church Postils, mid-1520's [taken from volume II:238-247 of 'The Sermons of Martin Luther', published by Baker Book House (Grand Rapids, Mi.)] This set of Luther's sermons is still available at a reasonable price from Christian bookshops.