“What evidence do you have of this?”
Pardon me, but I think perhaps you may find good information for your question in the book “Proof of Heaven”
http://www.amazon.com/gp/aw/d/1451695195?pc_redir=1409830334&robot_redir=1
The author is obviously a very intelligent man, having dedicated his life’s work to science and physically opening up people’s brains. He makes a very compelling argument for the existence of heaven. His experience of it changed his life so much that he now finds his life’s mission to integrate his knowledge of science and the physical universe with the gift he was given, that is, the spiritual foundation of everything: Love.
Fellow FReeper, if I were to ask of you one thing in this life that I thought would answer your questions on this topic of life after death of your body, it would be to read this book.
Religion has had 5,000 years to provide evidence for eternal life, and has failed. It would make sense that mankind would invent eternity for the mind, since our minds are all that we have. But everything we know about the universe says that nothing is eternal, and waking up from the Bronze Age point of view and making peace with that fact is the most adult decision one can make.
I'm actually familiar with Dr. Alexander from an Intelligence Squared debate he participated in. I just watched this debate last month, and would recommend it to everyone, as Sean Carroll and and Dr. Novella intricately pick apart Dr. Alexander's extremely subjective arguments (Ray Moody is more of a spectator, leaving poor Dr. Alexander outnumbered):