Jesus continues to do miracles, and the Pharisees ask for a sign from God. After all that Jesus has done, they want more! Compare this to Peter’s response. He was an uneducated fisherman, but had enough sense to see Jesus was the Christ, who had been promised to the Jews by God to save them. Mark then signals a turning point in Jesus’ ministry by telling us he is beginning to prepare his followers for his death.
Maybe you have met someone who has said they would believe the Bible if one of those miracles in the Bible happened right in front of them. Here we see people who had miracles happen right in front of them; some believed and some didn’t. It is no different today. Some hear the message of Jesus and see how he is at work today and believe, and others don’t. Our message is always the same; the response is up to the ones hearing it.