38One day some teachers of religious law and Pharisees came to Jesus and said, “Teacher, we want you to show us a miraculous dsign to prove your authority.”
39But Jesus replied, “Only an evil, adulterous generation would demand a miraculous sign; but the only sign I will give them is the sign of the prophet Jonah.40For as Jonah was in the belly of the great fish for three days and three nights, so will the Son of Man be in the heart of the earth for three days and three nights.
41“The people of Nineveh will stand up against this generation on judgment day and condemn it, for they repented of their sins at the preaching of Jonah. Now someone greater than Jonah is here—but you refuse to repent.42The queen of Sheba will also stand up against this generation on judgment day and condemn it, for she came from a distant land to hear the wisdom of Solomon. Now someone greater than Solomon is here—but you refuse to listen.
Jesus was obviously upset by them asking for a sign.  Had he not performed enough miracles?  What more could they want?  They Pharisees were looking for some “sign” but all Jesus was going to give them was his life and the changed lives of those he touched.  And that is still what Jesus gives to you and me.
We are required by Jesus to see him all around us, all the time.  He expects us to see him in the change lives of others, and for others to see him in our changed lives.   
He also told the Pharisees to find him in his own life and how it fulfilled prophecy.  That is why we read God’s word, the Bible.  Jesus points here to the sign of Jonah, but the Bible is full of such signs.  When we read it and study it and get to know it, our faith will literally explode because  Jesus so clearly fulfills and complete all that is predicted concerning Him.  But we need to read and study the Bible, or that sign will not be there for us. Beginner’s Online Bible Study *obbs*