Then some of the scribes and Pharisees said to him, "Teacher, we wish to see a sign from you." He said to them in reply, "An evil and unfaithful generation seeks a sign, but no sign will be given it except the sign of Jonah the prophet. Just as Jonah was in the belly of the whale three days and three nights, so will the Son of Man be in the heart of the earth three days and three nights. At the judgment, the men of Nineveh will arise with this generation and condemn it, because they repented at the preaching of Jonah; and there is something greater than Jonah here. At the judgment the queen of the south will arise with this generation and condemn it, because she came from the ends of the earth to hear the wisdom of Solomon; and there is something greater than Solomon here. (Mt 12:38-42)
Scribes and Pharisees ask for a sign. They do not accept the reality but a sign. Sign is only a pointer to the reality. That is why Jesus condemns this generation as wicked. They are wicked not because of any moral standard but because they accept signs and believe in signs.
But even this wicked generation will be given a sign. Provided they get the right message from the reality. All the signs are to point out to the reality Jesus’ death and resurrection or whatever points out to the reality of death and resurrection will be the sign.
But signs and realities focus on one message: repentance. If there is no repentance then all the rest are waste. Prophecy (Jonah) and Wisdom (Solomon) are useless if they do not lead people to repentance. In fact they all reveal something greater and that is Jesus.
