“... none will be given it except the sign of Jonah.” (Matthew 16:1-4)

The Pharisees and Sadducees came to Jesus and tested him by asking him to show them a sign from heaven. He replied, "When evening comes, you say, 'It will be fair weather, for the sky is red,' and in the morning, 'Today it will be stormy, for the sky is red and overcast.' You know how to interpret the appearance of the sky, but you cannot interpret the signs of the times. A wicked and adulterous generation looks for a sign, but none will be given it except the sign of Jonah." Jesus then left them and went away. (Matthew 16:3-4)

Why is Jesus talking about 'signs'?

Because the Pharisees and Sadducees had a lack of faith in God, they were most interested in seeing some sort of 'sign' before accepting that Jesus was God's representative.

Jesus' reply here illustrates the pragmatic reality of 'signs.' He illustrates how one can simply read the signs about future weather just by looking at the sky. The sky will show signs of future weather. It is a practical matter.

But then Jesus states that instead of seeing practical signs about the current society, those who are “wicked and adulterous” are looking for some kind of "miraculous sign" from God's representative.

This is because they were not sincerely seeking God. They also were not examining history. 

What does Jesus mean by "signs of the times"? Jesus is speaking of the state of that society at the time. He is seeing the natural progression for those within that society that had become less devoted to God.

What is the 'sign of Jonah'?

These points are clarified by Jesus' reference to “the sign of Jonah.” What is “the sign of Jonah?” 

In the Book of Jonah, we can read the beautiful story of Jonah. Jonah, a devoted servant of God, was requested by the Supreme Being to go to the great city of Nineveh to give them a message because the people of the city had abandoned their faith in the Supreme Being. 

They were living in ways that were not good for their spiritual lives. God asked Jonah to go to the city and preach to them to abandon their ways.

However, Jonah tried to escape the request of the Supreme Being by traveling by boat to Tarshish. As he was on the boat a great storm came up, and the other sailors were forced to put Jonah overboard to avoid the boat capsizing.

As soon as they did, the storm calmed. Then Jonah found himself swallowed by a large fish and for three days, Jonah lived inside the large fish until he was deposited onto the beach. During those three days, Jonah came to terms with the Supreme Being and committed to God a great prayer, often referred to as Jonah's prayer:
“In my distress I called to the Lord, and he answered me. From the depths of the grave I called for help, and You listened to my cry. You hurled me into the deep, and the very heart of the seas, and the currents swirled about me; all Your waves and breakers swept over me. I said, 'I have been banished from Your sight; yet I will look again toward Your holy temple.' The engulfing waters threatened me, the deep surrounded me; seaweed was wrapped around my head. To the roots of the mountains I sank down; the earth beneath barred me in forever. But You brought my life up from the pit, O Lord my God. When my life was ebbing away, I remembered You, Lord, and my prayer rose to You, to your holy temple. Those who cling to worthless idols forfeit the grace that could be theirs. But I, with a song of thanksgiving, will sacrifice to You. What I have vowed I will make good. Salvation comes from the Lord.” (Jonah 2:1-9)
This prayer goes to the heart of Jesus' message. Here Jonah submitted to the Supreme Being as he found himself in danger, and was given mercy and rescued by God. Once rescued, Jonah went on to follow God's instructions and preach to the city of Nineveh. He told them that they had forty days to make changes or the city would be destroyed. 

The people of the city responded, and the Book of Jonah closes with God clarifying to Jonah His compassion for the city's 120,000 people.

This “sign of Jonah” illustrates Jesus' role as well. Jesus is being sent by the Supreme Being to save the people of Israel. He was sent with a message. And what is that message? The same message that Jonah delivered, and the same message our current generation needs to hear: That we need to return to our loving service relationship with our Best Friend and ultimate Savior, the Supreme Being.

Why does 'a wicked and adulterous generation look for a sign'?

The word "generation" is quite misleading here. This word is being translated from the Greek word, γενεά (genea). Yes, this can relate to genealogy, but it also means, "the whole multitude of men living at the same time." 

Thus, a better translation of this word in Jesus' context would be "society," or "culture."

Yes, Jesus is speaking of a particular society or culture that at the time was focused upon giving notice to those who exhibited "signs."

What makes a society or culture “wicked”? It is turning away from our relationship with the Supreme Being. This produces a consciousness of self-centeredness.

A consciousness of self-centeredness produces a demand for knowing the future. This in turn makes us hungry to see a sign that indicates what happens in our future.

Jesus is indicating that seeking signs in order to know the future is not a suggested focus of our attention. We are here in the physical world to learn, and the future will play out according to what we need to learn, and how fast we learn those lessons.

The physical world plays out our consciousness and teaches us lessons that ultimately relate to love. Here we have a constant opportunity to give love to others, have compassion and mercy on others, and live a life that is true to ourselves and others. When we take that opportunity we gradually redevelop our spiritual consciousness, which is based on our loving nature.

By nature, we need to love and we need to be loved. Here in the physical world, we can pretend that others love us, and we can tell others that we love them. But true love originates from the Supreme Being. And by receiving His unconditional love we can know how to love others.

Yet we find many instances in the Old Testament that make God appear as an angry and jealous ruler who is also vengeful. How can we love someone like that?

This was part of Jesus' mission - to dispel the notion that God is someone to be feared. The Supreme Being is the most beautiful, gracious and compassionate being. He is the Source of love.

As Jesus pointed out regarding the Pharisees and Sadducees, they were not to be trusted. And the mischaracterization of God and mistranslation of the Old Testament Books was a result of such an institutionalized mishandling of Jesus' teachings and the Prophets' teachings.