You can see all the lectionary readings for Proper 19, Year B by clicking here. I have chosen to discuss the passage from the Gospel of Mark.
In today’s passage Jesus and his followers are traveling around and he asks them who people say that he is. They respond with various answers: John the Baptist, Elijah returned, one of the prophets. He then asks who they say he is and Peter says, “You are the Messiah.”
He tells them not to tell anyone and explains that he will suffer many things–that he will not be accepted by the leaders and that he will be killed and rise again after three days.
Peter takes him aside and criticizes him (like a friend might criticize another for being negative, I suppose). But Jesus rebuked him saying, “Get away from me, Satan! You don’t care about the same things God does. You care only about things that people think are important.”
Jesus tells the crowd they have to stop thinking only of themselves. He tells them to save the life they have, they must lose it. They must take up the cross to follow him. “It is worth nothing for you to have the whole world if you yourself are lost. You could never pay enough to buy back your life.”