During Jesus' time there were two sects, the Sadducees and Pharisees. The Sadducees favored the Roman government due to the power it allotted them; whereas, the Pharisees wanted to break free from the Romans. These two groups were bitter enemies until they united in their desire to destroy Jesus.  

Upon seeing Jesus, the Pharisees and Sadducees asked to see another sign to prove that Jesus was God. Jesus responded by saying, “Evil and sinful people ask for a miracle as a sign, but they will not be given any sign, except the sign of Jonah”.  

Jonah was swallowed by a whale after attempting to run from God's instructions. He spent three days in the belly of the whale before being spit out onto the shore. At that time he went to Nineveh and warned the people to turn from their sins and they did.  

Similarly, Jesus was to spend three days in the belly of the earth and then he would be resurrected. Indeed, this would be another sign for everyone as Jesus was predicting the future. Unfortunately, the Pharisees and Sadducees did not repent due to their hardened hearts of unbelief. In contrast, the people of Nineveh believed and repented without a sign and they will be in heaven.  

Today, there are many people that ask God to show them a sign so that they can believe. One must remember that he did not work miracles on demand for the Pharisees or for Satan in the wilderness. Jesus will not work a miracle to satisfy our unbelief and pride.  

We are naturally at odds with God and aligned with Satan by our sinful nature. When we accept Jesus and surrender our will, Jesus comes into our lives and changes our hearts. With Jesus in our hearts, the bondage toward sinful practices is broken, which is the greatest sign of all. Jesus says, “Also, I will teach you to respect me completely, and I will put a new way of thinking inside you. I will take out the stubborn hearts of stone from your bodies and I will give you obedient hearts of flesh.   Ezekiel 36:26.  

We are naturally inclined to seek self-gratification and human approval. As Jesus enters our hearts, our focus will shift away from ourselves and toward Jesus. We simply need to check doubt at the door and ask Jesus to live in our hearts.