What does Mark 16:12 mean?

These verses were most likely added to Mark, well after the original writing, to correspond with Luke 24:13–35. Two Christ-followers, including Cleopas (Luke 24:18), are walking from Jerusalem to the village of Emmaus. Jesus joins them but doesn't reveal who He is. He asks the two men what they are discussing. They explain that they follow a man who they'd believed to be a prophet and thought might just be the Messiah who would rescue Israel from Roman rule. But the man was crucified and died.

The two men go on to say that some of the women in their company had gone to the tomb and found it empty. Angels told the women that this man is alive. Two men also found the tomb empty, but none of them knew what it meant. Jesus responds by explaining how the Old Testament specifically says the Messiah must die and be raised again. He covers the books of Moses and all the prophets.

The beginning of Genesis covers the creation of the world through the moment God calls Abraham to be the father of His chosen people. The rest of the Old Testament covers the history of the Jews and their neighbors. Because of the inclusion of the Mosaic Law and the focus on the Jews' inability to follow it, a surface-level reading of the Old Testament infers the text is about obedience and punishment.

Jesus explains that the text is actually about how the world cannot obey God. We need a Savior, one who is sinless: a perfect sacrifice to die and rise again for our sins.

The two men invite their companion to stay for a meal. It isn't until Jesus takes the bread, breaks it, and prays over it that they realize who He is. Jesus vanishes from their sight and they rush back to Jerusalem and report to the disciples.