"You're pretty sure of yourself on those points without evidence..."
And the pope is pretty sure I'm wrong without evidence. The claim that thier is a heaven, and the claim that there is not, have the same amount of evidence to back them up.
Where is the evidence to the contrary?
The Pope is not making this claim on his own and he is not the source of the claim. This claim was demonstrated by Jesus Christ, by his words and his resurrection.