Mat 12:38 Then some of the scribes and Pharisees said to Him, "Teacher, we want to see a sign from You."
Mat 12:39 But He answered and said to them, "An evil and adulterous generation craves for a sign; and
yet no sign will be given to it but the sign of Jonah the prophet;
Mat 12:40 for just as JONAH WAS THREE DAYS AND THREE NIGHTS IN THE BELLY OF THE SEA MONSTER, so will the Son of Man be three days and three nights in the heart of the earth.
Only one with a cynical mind would disregard the proof in front of him and demand the sign of his own choice. If God has chosen to create this world and recreate it in such a way as to test mankind then you will be one of those that indeed fail the test, if you do not heed the signs that have already been given.