As he neared Damascus on his journey, suddenly a light from heaven flashed around him. He fell to the ground and heard a voice say to him, "Saul, Saul, why do you persecute me?" (Acts 9:3-4)
I knew a man in Christ above fourteen years ago, (whether in the body, I cannot tell; or whether out of the body, I cannot tell: God knoweth) such an one caught up to the third heaven. And I knew such a man, (whether in the body, or out of the body, I cannot tell: God knoweth) How that he was caught up into paradise, and heard unspeakable words, which it is not lawful for a man to utter. (1 Corinthians 12:2-4)
There is also a bunch of evidence in the Gnostic texts.
Did Paul have a Near Death Experience? If so, what is the difference between the the letters of paul and the books and writings of people who have had NDEs?