Your assertions != evidence. There is this pesky thing called the Resurrection, which permenantly changed mankind like no other event in history. The miracle of the Resurrection of Jesus Christ proved to the world the authority of His words.
The Scribes and Pharisees Ask for a Sign
Mat 12:38-41
38 Then some of the scribes and Pharisees answered, saying, "Teacher, we want to see a sign from You."
39 But He answered and said to them, "An evil and adulterous generation seeks after a sign, and no sign will be given to it except the sign of the prophet Jonah.
40 For as Jonah was three days and three nights in the belly of the great fish, so will the Son of Man be three days and three nights in the heart of the earth.
41 The men of Nineveh will rise up in the judgment with this generation and condemn it, because they repented at the preaching of Jonah; and indeed a greater than Jonah is here.