Luke does not share Mark’s view that Jesus’ death brought about an atonement for sins. In Mark’s Gospel Jesus spoke of his coming death as bringing salvation: “The Son of Man came not to be served but to serve, and give his life as a ransom for many” (Mark 10:45). Here Jesus’ death ransoms others who deserve to die – that is, it is a substitution for the death of others. It is striking indeed that Luke omits this verse. And why does he do so? This may sound odd, but it is because for him, Jesus’ death does not bring atonement for sin.
Then why does Jesus die? For Luke, Jesus dies because he is a righteous prophet who was rejected by his own people in a severe miscarriage of justice. And how does Jesus’ death then lead to the salvation from sin? When you read volume two of this author’s work, the book of Acts, you will find the answer quite clearly, When the apostles in Acts try to convert others to believe in Jesus, they proclaim that Jesus’ innocent death shows how sinful people are. When people recognise their sinfulness, they break down and confess to God, begging for his forgiveness. And then God forgives them. For Luke Jesus’ death is not an atonement for the sins of others; it is a death that leads people to ask for forgiveness.
Let me illustrate the difference. If you owe me a hundred dollars but cannot pay, there are a couple of ways we could deal with your dilemma. You could find someone else to pay your debt for you. That would be atonement (Christ dies for the sake of others). As an alternative, you could ask me to forgive you the debt, so that no one needs to pay. If I agree, then that would be like forgiveness (Christ’s death leads person to ask for forgiveness). Mark understands Jesus’ death as atonement and Luke as an occasion to ask for forgiveness. It’s a big difference.
Extract from The Bible: A Historical and Literary Introduction, by renowned biblical scholar Dr Bart Ehrman, page 281