I could never wrap around the idea of forgiveness. Forgiveness for what, what did I do??
Atonement = pay my debt. I never borrowed anything from God.
But your right, I always noticed that Luke talks about a preaching work that is different from the preaching work that Matthew talks about.
(Luke 24:47) . . .and on the basis of his name repentance for forgiveness of sins would be preached in all the nations. . .
(Matthew 24:14) 14 And this good news of the kingdom will be preached in all the inhabited earth for a witness to all the nations; . . .
Luke preaches forgiveness while Matthew preaches the Kingdom.
Paul was good at tying in the sacrifices of Jewish Law with the death of Jesus and Mark evidently adopted Paul's views since they hung around quit a bit.
(Acts 12:25) . . .As for Bar′na·bas and Saul, after having fully carried out the relief ministration in Jerusalem, they returned and took along with them John, the one surnamed Mark.