red sky at night, sailors delight...

Matthew 16:1-4

The key words in this passage are sign, wicked and adulterous. I think it is significant that the Pharisees and Sadducees have made an alliance to confront Jesus; apparently both recognized that Jesus was beginning to threaten their positions. The Pharisees likely threatened by the authourity and popularity of Jesus and the Sadducees recognizing that the movement Jesus was starting was going to upset the tenuous peace that they had worked so hard to establish with the Roman authourities (and the power they achieved through that agreement).
In response to their request for a sign, Jesus responds with a well-known proverb. In elementary I heard a similar one: red sky at night, sailors delight; red sky in the morning, sailors take warning. Jesus' point is that they can read the signs in the sky but they can't read the even more obvious signs that point to Jesus being the Messiah.
Jesus leaves them with the sign of Jonah. I'm not sure if the sign of Jonah was a well known prophecy or sign in Jesus' culture or if it had ever been connected to the Messiah. I'm not sure if the Pharisees and Sadducees would have understood what Jesus was talking about, even if they carefully studied the book of Jonah. The sign is pretty obscure - or at least would have been at the time: I'm pretty sure that Jesus was referring to his being in the belly of the earth for three days, just as Jonah was in the belly of the fish for three days. But that hadn't happened yet and could only be seen as a sign in retrospect. Perhaps Jesus was warning them that because they had missed, or failed to acknowledge, the signs of his authourity already (ie his healings, miracles, etc.) that they would likely even miss, or fail to acknowledge, the most obvious sign of his identity; his resurrection.
Again, this forces me to ask myself if I am missing the work of Christ in this world? Have I become so comfortable in my religion that I fail to acknowledge the work and authourity of Christ in anything outside of my box? I don't think I have got to the same place as the Pharisees and Sadducees yet but I can see those tendencies in myself and I pray desperately that I would not become so rigid and hard as they have become. I pray that God would continue to keep my sensitive to his work and the authourity of Christ and I would not let structure or tradition dictate what God can or cannot do.